Non-aqueous ink jet composition

ABSTRACT

A non-aqueous ink jet composition includes a pigment component containing a diketopyrrolopyrrole pigment and an organic solvent. The organic solvent contains glycol ethers. The amount of dissolved nitrogen in the non-aqueous ink jet composition is 90 mass ppm or less based on the total amount of the non-aqueous ink jet composition.

BACKGROUND

1. Technical Field

The present invention relates to a non-aqueous ink jet composition.

2. Related Art

Ink jet recording methods can record highly fine images with relativelysimple apparatuses and have been rapidly developing in various fields.Among them, various studies for more stably giving recorded mattershaving high quality have been being carried out.

For example, JP-A-2014-91795 is subjected to provide an ink exhibitingexcellent discharge stability and discloses an ink for ink jet printingcontaining water, a water-soluble organic sorbent, a coloring material,and an polyol that is dissolved in water in an amount of 10 wt % or lessin a standard state (25°, 1 at.) and having a weight ratio of thedissolved nitrogen concentration to the dissolved oxygen concentrationof 10/1 or more.

For example, JP-A-2009-227812 is subjected to provide, in particular, anoil-based ink set having high color reproducibility and providing imageshaving high color intensity and discloses an oil-based ink set includinga first oil-based ink, a second oil-based ink, and a third oil-based inkeach independently having a wavelength region in which the reflectivityon a recording medium changes from 80% to 5% within a wavelength regionrange of 400 to 700 nm, wherein the reflectivity of the second oil-basedink is successively higher than that of the first oil-based ink in thewavelength region in which the reflectivity of the first oil-based inkchanges from 80% to 5%; the reflectivity of the third oil-based ink issuccessively higher than that of the second oil-based ink in thewavelength region in which the reflectivity of the second oil-based inkchanges from 80% to 5%; and the coloring materials in the firstoil-based ink, the second oil-based ink, and the third oil-based ink aredifferent from one another.

However, the ink for ink jet printing described in JP-A-2014-91795 is anaqueous ink jet composition containing water and is not any non-aqueousink jet composition substantially not containing water. Aqueous inkcompositions and non-aqueous ink jet compositions differ from each otherin required characteristics and physical properties and raw materialsnecessary for the characteristics.

Known non-aqueous ink jet compositions can include pigment componentscontaining diketopyrrolopyrrole pigments for improving the intensity ofthe resulting recorded matters. However, the pigments contained in thecompositions cause uneven aggregation in the resulting recorded matters,resulting in poor intensity of the recorded matters. In addition,non-aqueous ink jet compositions are required to provide recordedmatters having excellent intensity and at least have excellent dischargestability.

The oil-based ink described in JP-A-2009-227812 contains a pigmenthaving an average particle diameter larger than a prescribed value,resulting in poor storage stability.

SUMMARY

An advantage of some aspects of the invention is to provide anon-aqueous ink jet composition that has excellent discharge stabilityand can form recorded matters having excellent intensity.

The present inventors have diligently studied to solve theabove-described problems and, as a result, have found that a non-aqueousink jet composition including a pigment component at least containing adiketopyrrolopyrrole pigment and a prescribed organic solvent and havinga dissolved nitrogen content not higher than a predetermined amount hasexcellent discharge stability and can form recorded matters havingexcellent intensity, and have accomplished the present invention.

That is, a first aspect of the present invention relates to anon-aqueous ink jet composition including a pigment component containinga diketopyrrolopyrrole pigment and an organic solvent. The organicsolvent contains glycol ethers, and the amount of dissolved nitrogen inthe organic solvent is 90 mass ppm or less based on the total amount ofthe non-aqueous ink jet composition. The factors of such a non-aqueousink jet composition of the present invention that can solve theabove-described problems are presumed, but not limited to, as follows:Although the diketopyrrolopyrrole pigment itself has excellentintensity, non-aqueous ink jet compositions including pigment componentsmerely containing the diketopyrrolopyrrole pigment cause unevenaggregation in the recorded matters, resulting in insufficient intensityof the recorded matters. In order to prevent the uneven aggregation, itis conceivable to use glycol ethers in the organic solvent. The glycolethers have high solubility to nitrogen and oxygen in the air and aretherefore contaminated with large amounts of nitrogen and oxygen asimpurities. In addition, if the non-aqueous ink jet compositionincluding such organic solvents is left in, for example, the atmosphericair, the composition absorbs nitrogen and oxygen in the air with time.However, in a non-aqueous ink jet composition containing dissolvednitrogen and oxygen, gas is generated in the composition by variouschanges (changes in temperature and pressure) at discharge by an ink jetmethod, resulting in poor discharge stability. In contrast, thediketopyrrolopyrrole pigment has high hydrophobicity. Accordingly, anon-aqueous ink jet composition containing this pigment relativelyreadily deteriorates the dispersibility of the pigment by being incontact with water, resulting in poor storage stability. Accordingly,the non-aqueous ink jet composition according to the present inventionincludes both a pigment component containing a diketopyrrolopyrrolepigment and the glycol ethers and contains dissolved nitrogen in anamount regulated to 90 mass ppm or less. As a result, the non-aqueousink jet composition according to the present invention prevents unevenaggregation of the diketopyrrolopyrrole pigment to effectively utilizethe excellent intensity of the pigment and also has excellent dischargestability.

In the non-aqueous ink jet composition according to the presentinvention, the amount of dissolved nitrogen is preferably 10 mass ppm ormore based on the total amount of the non-aqueous ink jet composition;and the glycol ethers preferably includes a glycol diether representedby Formula (1) and/or a glycol monoether represented by Formula (2):R¹O—(R³O)_(m)—R²  (1)where, R¹ and R² each independently represent an alkyl group having 1 to7 carbon atoms, R³ represents an alkylene group having 1 to 3 carbonatoms, and m represents an integer of 1 to 7,OH—(R⁵O)_(n)—R⁴  (2)where, R⁴ represents an alkyl group having 1 to 7 carbon atoms, R⁵represents an alkylene group having 1 to 3 carbon atoms, and nrepresents an integer of 1 to 7.

In the non-aqueous ink jet composition according to the presentinvention, the amount of the pigment component is preferably 1.0 mass %or more and 5.0 mass % or less based on the total amount of thenon-aqueous ink jet composition; the amount of the glycol ethers ispreferably 10 mass % or more and 90 mass % or less based on the totalamount of the non-aqueous ink jet composition; the organic solventpreferably further contains a cyclic lactone; and the compositionpreferably further contains a vinyl chloride resin.

In addition, the ink jet recording method according to the presentinvention includes a step of performing recording on a recording mediumby an ink jet method using the non-aqueous ink jet composition accordingto the present invention.

The present inventors have also diligently studied to solve theabove-described problems and, as a result, have found that a non-aqueousink jet composition including a pigment component at least containing adiketopyrrolopyrrole pigment and a prescribed organic solvent can formrecorded matters having excellent intensity, and have accomplished thepresent invention.

That is, a second aspect of the present invention relates to anon-aqueous ink jet composition including a pigment component containinga diketopyrrolopyrrole pigment and an organic solvent. The organicsolvent contains a glycol ether, and the pigment has an average particlediameter of 100 nm or more and 240 nm or less. The factors of such anon-aqueous ink jet composition that can solve the above-describedproblems are presumed, but not limited, as follows: Known non-aqueouscompositions containing pigments having an average particle diameterhigher than 240 nm can improve the intensity of the resulting recordedmatters. However, excellent discharge stability cannot be obtainedmainly due to the pigments having an average particle diameter higherthan 240 nm. In contrast, the non-aqueous composition of the embodimentenhances the color developing property of the pigment itself byemploying a diketopyrrolopyrrole pigment and prevents occurrence ofuneven aggregation in the resulting recorded matters by containing theglycol ether. As a result, even if the pigment used has an averageparticle diameter of 240 nm or less, the resulting recorded matters havesufficiently excellent intensity. In addition, excellent dischargestability can be achieved mainly due to the average particle diameter of240 nm or less of the pigment.

In the non-aqueous ink jet composition according to the presentinvention, the diketopyrrolopyrrole pigment is preferably adiketopyrrolopyrrole red pigment, and the organic solvent preferablycontains a glycol diether represented by Formula (1) and a glycolmonoether represented by Formula (2):R¹O—(R³O)_(m)—R²  (1)where, R¹ and R² each independently represent an alkyl group having 1 to7 carbon atoms, R³ represents an alkylene group having 1 to 3 carbonatoms, and m represents an integer of 1 to 7,OH—(R⁵O)_(n)—R⁴  (2)where, R⁴ represents an alkyl group having 1 to 7 carbon atoms, R⁵represents an alkylene group having 1 to 3 carbon atoms, and nrepresents an integer of 1 to 7.

In the non-aqueous ink jet composition according to the presentinvention, the amount of the pigment component is preferably 1.0 mass %or more and 5.0 mass % or less based on the total amount of thenon-aqueous ink jet composition; the total amount of the glycol dietherand the glycol monoether is preferably 10 mass % or more and 90 mass %or less based on the total amount of the non-aqueous ink jetcomposition; and the organic solvent preferably further contains acyclic lactone. The non-aqueous ink jet composition preferably furtherincludes a vinyl chloride resin.

In addition, the ink jet recording method according to the presentinvention includes a step of performing recording on a recording mediumby an ink jet method using the non-aqueous ink jet composition accordingto the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a perspective view schematically illustrating theconfiguration of a printer according to an embodiment of the presentinvention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

A first aspect (hereinafter, referred to as “the embodiment”) forimplementing the present invention will now be described in detail withreference to the drawing as needed. The following embodiment isexemplification for explaining the present invention and is not intendedto limit the present invention to the following contents. The presentinvention can be implemented by being appropriately modified within thescope of the gist. In the drawing, the same elements are denoted by thesame reference signs, and the duplicated explanation is omitted. Thepositional relation such as up and down and right and left is based onthe positional relation shown in the drawing, unless otherwisespecified. The dimensional ratio is not limited to that shown in thedrawing.

Non-Aqueous Ink Jet Composition

The non-aqueous ink jet composition (hereinafter, also simply referredto as “ink jet composition”, “non-aqueous composition”, or“composition”) of the embodiment includes a pigment component containinga diketopyrrolopyrrole pigment and an organic solvent. In thenon-aqueous ink jet composition, the organic solvent contains glycolethers, and the amount of dissolved nitrogen is 90 mass ppm or lessbased on the total amount of the non-aqueous ink jet composition.

The composition of the embodiment includes a pigment componentcontaining a diketopyrrolopyrrole pigment and also the glycol ethers andincludes dissolved nitrogen in an amount of 90 mass ppm or less, andthereby has excellent discharge stability and provides excellentintensity to the resulting recorded matters. The factors thereof arepresumed (but not limited to) as follows. Although thediketopyrrolopyrrole pigment itself has excellent intensity, non-aqueousink jet compositions including pigment components merely containing thediketopyrrolopyrrole pigment cause uneven aggregation in the resultingrecorded matters, resulting in insufficient intensity of the recordedmatters. In order to prevent the uneven aggregation, it is conceivableto use glycol ethers as the organic solvent. However, the glycol ethershave high hygroscopic properties to nitrogen and oxygen in the air andare therefore contaminated with large amounts of nitrogen and oxygen asimpurities. In addition, if the non-aqueous ink jet compositionincluding such an organic solvent is left in, for example, theatmospheric air, the composition absorbs nitrogen and oxygen in the airwith time. A non-aqueous ink jet composition containing dissolvednitrogen or oxygen generates gas in the composition by various changes(changes in temperature and pressure) when discharged by an ink jetmethod, resulting in poor discharge stability. Accordingly, thenon-aqueous ink jet composition according to the embodiment includesboth a pigment component containing a diketopyrrolopyrrole pigment andthe glycol ethers and regulates the amount of dissolved nitrogen to 90mass ppm or less. As a result, the non-aqueous ink jet compositionaccording to the embodiment prevents uneven aggregation of thediketopyrrolopyrrole pigment to effectively utilize the excellentintensity of the pigment and has excellent discharge stability.

In the embodiment, the term “non-aqueous composition” refers to acomposition of which the main solvent is of other than water, such as anorganic solvent. Herein, the term “main solvent” indicates that theamount of the solvent in a composition is 50 mass % or more, preferably70 mass % or more, and more preferably 90 mass % or more based on 100mass % of the composition. In addition, it is preferable that water isnot intentionally added to a composition as a main solvent component inpreparation of the composition, and it is preferable that water isinevitably contained in a composition as an impurity. The amount ofwater in the composition is preferably 3.0 mass % or less, morepreferably 2.0 mass % or less, more preferably 1.0 mass % or less, andmore preferably 0.5 mass % or less based on 100 mass % of thecomposition. The lower limit of the water content is not particularlylimited and may be lower than the detection limit or may be 0.01 mass %.

In the embodiment, the term “amount of dissolved nitrogen” refers to theamount of nitrogen dissolved in a non-aqueous composition and is anindicator of the amount of air dissolved in the non-aqueous composition.The amount of dissolved nitrogen is 90 mass ppm or less, preferably 10mass ppm or more and 90 mass ppm or less, more preferably 20 mass ppm ormore and 90 mass ppm or less, more preferably 30 mass ppm or more and 75mass ppm or less, and most preferably 40 mass ppm or more and 60 massppm or less based on the total amount of the non-aqueous composition.The non-aqueous composition has excellent discharge stability byrestricting the amount of dissolved nitrogen to 90 mass ppm or less. Anamount of dissolved nitrogen of 20 mass ppm or more provides excellentintensity to the resulting recorded matters and can be easily achieved,for example, by deaeration treatment of the non-aqueous composition fora short time, resulting in a tendency of manufacturability to beexcellent. In particular, if the amount of dissolved nitrogen isregulated to 20 mass ppm or more, a non-aqueous composition containing adiketopyrrolopyrrole pigment can shorten the time for deaerationtreatment, compared with that containing another pigment. In addition, anon-aqueous composition containing dissolved nitrogen in an amount of 20mass ppm or more does not significantly absorb air, unlike non-aqueouscompositions in an excessively deaerated state in which the amount ofdissolved oxygen is lower than the lower limit, and thereby tends toprevent deterioration of the discharge stability.

The amount of dissolved nitrogen in the composition can be controlledby, for example, removing air composed of nitrogen and oxygen from eachcomponent of the composition, specifically, removing air composed ofnitrogen and oxygen contaminating the organic solvent; removing aircomposed of nitrogen and oxygen from the composition; or preventing aircomposed of nitrogen and oxygen from contaminating the compositionduring preparation of the composition. Among these methods, the methodremoving air composed of nitrogen and oxygen contaminating the organicsolvent is more specifically performed by reduced pressure treatment orheating treatment of the composition described below. The amount ofdissolved nitrogen can be measured by a method described in examplesbelow. For example, the amount of dissolved nitrogen in the compositionimmediately before the use by means of an ink jet recording apparatus ismeasured.

The non-aqueous ink jet composition of the embodiment includes a pigmentand an organic solvent described below. Compositions containing solventsare roughly classified into two: a real-solvent (high organic solvent)composition and an eco-solvent (low organic solvent) composition. Theeco-solvent composition is a low-odor and human and environment-friendlycomposition, and the organic solvent contained in the composition doesnot fall under the category of organic solvents defined by theIndustrial Safety and Health Act, does not fall under the categories ofClass-1 and Class-2 organic solvents defined by the Ordinance OnPrevention of Organic Solvent Poisoning, and does not fall under thecategory of organic solvents requiring local exhaust ventilation inindoor workplaces defined as the installation environment by the FireService Act. Although the non-aqueous composition of the embodiment maycontain an organic solvent that can be used in real-solvent compositionsor an organic solvent that can be used in eco-solvent compositions,preferred is an organic solvent that can be used in eco-solventcompositions.

The “ink jet composition” in the embodiment can be used in a variety ofpurposes as a composition to be discharged by an ink jet method, and thepurposes are not limited. Specifically, the composition is used, forexample, as a composition for inks. The composition of the embodimentwill now be described in more detail with a case of being used as an inkcomposition for ink jet recording (hereinafter, also simply referred toas “ink composition”), which in one embodiment of ink jet compositions,but the composition of the embodiment is not limited thereto.

Pigment

The pigment component of the embodiment may contain any pigment as longas a diketopyrrolopyrrole pigment is contained, and may contain only adiketopyrrolopyrrole pigment or may contain a mixture of adiketopyrrolopyrrole pigment and a pigment other than thediketopyrrolopyrrole pigment (hereinafter, also referred to as “otherpigment”). The composition of the embodiment including a pigmentcomponent containing a diketopyrrolopyrrole pigment can provideexcellent intensity to recorded matters. In addition, the compositioncontaining a diketopyrrolopyrrole pigment has excellent dischargestability compared with compositions containing other pigments. This isconjectured as follows. Since the diketopyrrolopyrrole pigment has highhydrophobicity and high affinity with a non-aqueous atmosphere, thepigment hardly contains micro bubble nuclei therein. As a result,bubbles are hardly generated in discharge by an ink jet method.Accordingly, it is also conjectured that the pigment component of theembodiment containing a diketopyrrolopyrrole pigment hardly causesdefects in discharge by relatively simple deaeration treatment even ifthe amount of dissolved nitrogen is large, compared with pigments otherthan the diketopyrrolopyrrole pigment, and hardly generate bubbles evenif the amount of the pigment is large, compared with other pigments, tohardly cause defects in discharge. In addition, it is conjectured asanother reason for the excellent discharge stability that excellentintensity can be provided to recorded matters by thediketopyrrolopyrrole pigment in a smaller amount compared with thecompositions containing other pigments (but, the factors are not limitedthereto).

The diketopyrrolopyrrole pigment may be any pigment having adiketopyrrolopyrrole skeleton. The diketopyrrolopyrrole skeleton mayinclude a substituent, such as an alkyl group, or may include nosubstituent (the case that the substituents are all hydrogen atoms).Examples of the diketopyrrolopyrrole pigment include, but not limitedto, red organic pigments, such as C.I. Pigment Red 254, C.I. Pigment Red255, C.I. Pigment Red 264, C.I. Pigment Red 270, and C.I. Pigment Red272; and orange organic pigments, such as C.I. Pigment Orange 71, C.I.Pigment Orange 73, and C.I. Pigment Orange 81. Among these pigments,from the viewpoint of forming recorded matters having more excellentintensity, preferred are the red organic pigments: C.I. Pigment Red 254,C.I. Pigment Red 255, and C.I. Pigment Red 264; more preferred are C.I.Pigment Red 254 and C.I. Pigment Red 255; and most preferred is C.I.Pigment Red 254. These diketopyrrolopyrrole pigments may be used aloneor as a mixture of two or more thereof.

The diketopyrrolopyrrole pigment is preferably a diketopyrrolopyrrolered pigment. The diketopyrrolopyrrole red pigment exhibits a red colorand has a diketopyrrolopyrrole skeleton, and examples thereof includediketopyrrolopyrrole red pigments mentioned above as red pigments.Herein, the term “exhibiting a red color” indicates that when the colorof a recorded matter formed by applying an ink jet composition to awhite recording medium so as to cover the entire surface is measured bycolorimetry using Spectrolino (manufactured by GretagMacbeth), the valueh in the L*C*h color space of the CIE standard colorimetric system is−30° to 45°, preferably −30° to 32°, more preferably −30° to 30°, andmost preferably −30° to 25°.

The amount of the diketopyrrolopyrrole pigment is not particularlylimited and is 30 mass % or more and 100 mass % or less, 50 mass % ormore and 100 mass % or less, or 70 mass % or more and 100 mass % or lessbased on the total amount (100 mass %) of the pigment component. The useof a composition containing the diketopyrrolopyrrole pigment in anamount within such a range tends to provide more excellent intensity.

The other pigment may be any pigment other than the diketopyrrolopyrrolepigment and can be, for example, inorganic pigments and organic pigmentsthat are usually contained in known non-aqueous ink compositions. Theseother pigments may be used alone or as a mixture of two or more thereof.

Examples of the organic pigment include, but not limited to, azopigments (e.g., azo lake, insoluble azo pigments, condensed azopigments, and chelate azo pigments), polycyclic pigments (e.g.,phthalocyanine pigments, perylene and perylene pigments, anthraquinonepigments, quinacridone pigments, dioxadine pigments, thioindigopigments, isoindolinone pigments, and quinophthalone pigments), dyelakes (e.g., basic dye lakes and acid dye lakes), nitro pigments,nitroso pigments, aniline black, and daylight fluorescent pigments.

Examples of the inorganic pigment include, but not limited to, carbonblack, titanium dioxide, silica, and alumina.

It is also preferred to use a red organic pigment (hereinafter, alsoreferred to as “other red organic pigment”) other than thediketopyrrolopyrrole pigment or an orange organic pigment (hereinafter,also referred to as “other orange organic pigment”) other than thediketopyrrolopyrrole pigment, as the other pigment, from the viewpointof discharge stability and abrasion resistance.

Examples of the other red organic pigment include, but not limited to,C.I. Pigment Red 2, C.I. Pigment Red 3, C.I. Pigment Red 5, C.I. PigmentRed 6, C.I. Pigment Red 7, C.I. Pigment Red 15, C.I. Pigment Red 16,C.I. Pigment Red 48:1, C.I. Pigment Red 53:1, C.I. Pigment Red 57:1,C.I. Pigment Red 122, C.I. Pigment Red 123, C.I. Pigment Red 139, C.I.Pigment Red 144, C.I. Pigment Red 149, C.I. Pigment Red 166, C.I.Pigment Red 170, C.I. Pigment Red 177, C.I. Pigment Red 178, C.I.Pigment Red 179, C.I. Pigment Red 194, C.I. Pigment Red 209, C.I.Pigment Red 222, and C.I. Pigment Red 224.

The other orange organic pigment is not particularly limited, andexamples thereof include C.I. Pigment Orange 31, C.I. Pigment Orange 43,and C.I. Pigment Orange 64.

The amount of the pigment component is preferably 0.5 mass % or more and10 mass % or less, more preferably 1.0 mass % or more and 7.0 mass % orless, and most preferably 2.5 mass % or more and 3.0 mass % or less,based on the total amount (100 mass %) of the composition. A pigmentcomponent content of 0.5 mass % or more tends to provide more excellentintensity to the resulting recorded matters, and a pigment componentcontent of 10 mass % or less tends to provide more excellent storagestability and discharge stability.

The organic solvent of the embodiment is not particularly limited aslong as glycol ethers are contained. The glycol ethers preferablyinclude a glycol diether represented by Formula (1) (hereinafter, alsoreferred to as “specific glycol diether”) from the viewpoint ofproviding recorded matters having more excellent abrasion resistance andalso the viewpoint of improving the dispersion stability. In addition,the glycol ethers preferably include a glycol monoether represented byFormula (2) (hereinafter, also referred to as “specific glycolmonoether”) from the viewpoint of providing recorded matters having moreexcellent intensity. Furthermore, the glycol ethers more preferablyinclude both the specific glycol diether and the specific glycolmonoether from the viewpoint of improving the dispersion stability andproviding recorded matters having more excellent intensity.R¹O—(R³O)_(m)—R²  (1)where, R¹ and R² each independently represent an alkyl group having 1 to7 carbon atoms, R³ represents an alkylene group having 1 to 3 carbonatoms, and m represents an integer of 1 to 7,OH—(R⁵O)_(n)—R⁴  (2)where, R⁴ represents an alkyl group having 1 to 7 carbon atoms, R⁵represents an alkylene group having 1 to 3 carbon atoms, and nrepresents an integer of 1 to 7.

Examples of the specific glycol diether include, but not limited to,ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethyleneglycol dibutyl ether, diethylene glycol dimethyl ether, diethyleneglycol diethyl ether, diethylene glycol ethyl methyl ether, diethyleneglycol dibutyl ether, triethylene glycol dimethyl ether, triethyleneglycol diethyl ether, triethylene glycol dibutyl ether, tetraethyleneglycol dimethyl ether, tetraethylene glycol diethyl ether, tetraethyleneglycol dibutyl ether, propylene glycol dimethyl ether, propylene glycoldiethyl ether, dipropylene glycol dimethyl ether, and dipropylene glycoldiethyl ether. Among these glycol diethers, preferred are diethyleneglycol ethyl methyl ether, diethylene glycol diethyl ether, andtetraethylene glycol dimethyl ether; and more preferred is diethyleneglycol ethyl methyl ether. The composition containing such a preferredspecific glycol diether tends to provide more excellent abrasionresistance to the resulting recorded matters and tends to have moreexcellent discharge stability. These specific glycol diethers may beused alone or in combination of two or more thereof.

The amount of the specific glycol diether is preferably 5.0 mass % ormore and 90 mass % or less, more preferably 10 mass % or more and 80mass % or less, and most preferably 20 mass % or more and 75 mass % orless based on the total amount (100 mass %) of the composition. Thecomposition containing the specific glycol diether within theabove-mentioned range tends to provide more excellent intensity to theresulting recorded matters and have more excellent discharge stability.Herein, the amount of the specific glycol diether in the composition isthe amount including the amount of the specific glycol diether containedin, for example, a dispersion.

Examples of the specific glycol monoether include, but not limited to,ethylene glycol monomethyl ether, ethylene glycol monoethyl ether,ethylene glycol mono-n-propyl ether, ethylene glycol monoisopropylether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether,ethylene glycol monophenyl ether, diethylene glycol monomethyl ether,diethylene glycol monoethyl ether, diethylene glycol monobutyl ether,triethylene glycol monomethyl ether, triethylene glycol monoethyl ether,triethylene glycol monobutyl ether, tetraethylene glycol monomethylether, tetraethylene glycol monoethyl ether, propylene glycol monomethylether, propylene glycol monoethyl ether, dipropylene glycol monomethylether, and dipropylene glycol monoethyl ether. Among these glycolmonoethers, preferred are ethylene glycol monobutyl ether, triethyleneglycol monobutyl ether, tetraethylene glycol monoethyl ether, anddipropylene glycol monoethyl ether; and more preferred is triethyleneglycol monobutyl ether. The composition containing such a preferredspecific glycol monoether tends to provide more excellent abrasionresistance to the resulting recorded matters and have more excellentdischarge stability. These specific glycol monoethers may be used aloneor in combination of two or more thereof.

The amount of the specific glycol monoether is preferably 5.0 mass % ormore and 80 mass % or less, more preferably 7.0 mass % or more and 50mass % or less, and most preferably 10 mass % or more and 20 mass % orless based on the total amount (100 mass %) of the composition. Thecomposition containing the specific glycol monoether within theabove-mentioned range tends to provide more excellent intensity to theresulting recorded matters and have more excellent discharge stability.Herein, the amount of the specific glycol monoether in the compositionis the amount including the amount of the specific glycol monoethercontained in, for example, a dispersion.

The amount of the glycol ethers is preferably 5.0 mass % or more and 95mass % or less, more preferably 10 mass % or more and 90 mass % or less,and most preferably 20 mass % or more and 85 mass % or less based on thetotal amount (100 mass %) of the composition. The composition containingthe glycol ethers within the above-mentioned range tends to provide moreexcellent intensity to the resulting recorded matters and have moreexcellent discharge stability. Herein, the amount of the glycol ethersin the composition is the amount including the amounts of the glycolethers contained in, for example, a dispersion.

The organic solvent may contain a glycol diether (hereinafter, alsoreferred to as “other glycol diether”) other than the specific glycoldiether and/or a glycol monoether (hereinafter, also referred to as“other glycol monoether”) other than the specific glycol monoether.Examples of the other glycol diether include heptaethylene glycoldimethyl ether. Examples of the other glycol monoether includeheptaethylene glycol monomethyl ether.

The organic solvent tends to provide more excellent abrasion resistanceto the resulting recorded matters and have more excellent storagestability by further containing a cyclic lactone. The cyclic lactone maybe any compound having a ring structure formed by ester bonds, andexamples thereof include γ-lactone having a five-membered ringstructure, δ-lactone having a six-membered ring structure, and ε-lactonehaving a seven-membered ring structure. Examples of the cyclic lactoneinclude, but not limited to, γ-butyrolactone, γ-valerolactone,γ-hexalactone, γ-heptalactone, γ-octalactone, γ-nonalactone,γ-decalactone, γ-undecalactone, δ-valerolactone, δ-hexalactone,δ-heptalactone, δ-octalactone, δ-nonalactone, δ-decalactone,δ-undecalactone, and ε-caprolactam. Among these cyclic lactones,preferred are γ-lactone having a five-membered ring structure andδ-lactone having a six-membered ring structure; more preferred areγ-butyrolactone, γ-valerolactone, and δ-valerolactone; and mostpreferred is γ-butyrolactone. The composition containing such a cycliclactone tends to provide further enhanced abrasion resistance. Thecyclic lactones may be used alone or in combination of two or morethereof.

The amount of the cyclic lactone is preferably 1.0 mass % or more and 50mass % or less, more preferably 3.0 mass % or more and 40 mass % orless, and most preferably 5.0 mass % or more and 30 mass % or less basedon the total amount (100 mass %) of the composition. A cyclic lactonecontent of 1.0 mass % or more tends to provide more excellent abrasionresistance, and a cyclic lactone content of 50 mass % or less tends toprovide more excellent intensity. Herein, the amount of the cycliclactone in the composition is the amount including the amount of thecyclic lactone contained in, for example, a dispersion.

The organic solvent (other organic solvent) other than the glycoldiether, the glycol monoether, and the cyclic lactone is preferably ahydrocarbon solvent, an alcohol solvent, and an ester solvent, and morepreferably an ester solvent.

The hydrocarbon solvent is not particularly limited, and examplesthereof include aliphatic hydrocarbons (e.g., paraffin and isoparaffin),alicyclic hydrocarbons (e.g., cyclohexane, cyclooctane, andcyclodecane), and aromatic hydrocarbons (e.g., benzene, toluene, xylene,naphthalene, and tetralin). The hydrocarbon solvent may be acommercially available one, and examples thereof include aliphatichydrocarbon solvents and alicyclic hydrocarbon solvents, such as IPSolvent 1016, IP Solvent 1620, and IP Clean LX (these are all tradenames, manufactured by Idemitsu Kosan Co., Ltd.), Isopar G, Isopar L,Isopar H, Isopar M, Exxsol D40, Exxsol D80, Exxsol D100, Exxsol D130,and Exxsol D140 (these are all trade names, manufactured by Exxon), NSClean 100, NS Clean 110, NS Clean 200, and NS Clean 220 (these are alltrade names, manufactured by JX Nippon Oil & Energy Corporation), andNaphtesol 160, Naphtesol 200, and Naphtesol 220 (these are all tradenames, manufactured by JX Nippon Oil & Energy Corporation); and aromatichydrocarbon solvents, such as Solvesso 200 (trade name, manufactured byExxon).

The alcohol solvent is not particularly limited, and examples thereofinclude methanol, ethanol, isopropanol, 1-propanol, 1-butanol,2-butanol, 3-pentanol, 2-methyl-1-butanol, 2-methyl-2-butanol, isoamylalcohol, 3-methyl-2-butanol, 3-methoxy-3-methyl-1-butanol,4-methyl-2-pentanol, allyl alcohol, 1-hexanol, 1-heptanol, 2-heptanol,and 3-heptanol.

The ester solvent is not particularly limited, and examples thereofinclude methyl acetate, ethyl acetate, n-propyl acetate, isopropylacetate, n-butyl acetate, isobutyl acetate, isopentyl acetate, sec-butylacetate, amyl acetate, methoxybutyl acetate (3-methoxybutyl acetate,3-methoxy-3-methyl-1-butyl acetate), methyl lactate, ethyl lactate,butyl lactate, methyl caprylate, methyl caprate, ethylene glycolmonomethyl ether acetate, ethylene glycol monoethyl ether acetate,propylene glycol monomethyl ether acetate, propylene glycol monoethylether acetate, diethylene glycol monomethyl ether acetate, diethyleneglycol monoethyl ether acetate, and diethylene glycol monobutyl etheracetate. Among these ester solvents, preferred are methoxybutyl acetate,methyl caprylate, methyl caprate, methyl lactate, and ethyl lactate.

The total amount of at least one of hydrocarbon solvents, alcoholsolvents, and ester solvents as the organic solvent is preferably 30mass % or more and 80 mass % or less, more preferably 40 mass % or moreand 60 mass % or less, and most preferably 45 mass % or more and 55 mass% or less based on the total amount (100 mass %) of the non-aqueouscomposition. The composition containing these solvents within such arange tends to provide more excellent intensity to the resultingrecorded matters and have more excellent discharge stability.

The amount of the organic solvent is preferably 35 mass % or more and 95mass % or less, more preferably 50 mass % or more and 90 mass % or less,and most preferably 60 mass % or more and 90 mass % or less based on thetotal amount (100 mass %) of the composition. Herein, the amount of theorganic solvent in the composition is the amount including the amount ofthe organic solvent contained in, for example, a dispersion.

Resin

The composition of the embodiment may further include a resin for mainlyadjusting the viscosity of the composition. Examples of the resininclude, but not limited to, acrylic resins; styrene acrylic resins;rosin-modified resins; phenolic resins; terpene-based resins; polyesterresins; polyamide resins; epoxy resins; vinyl chloride resins, such asvinyl chloride-vinyl acetate copolymer resins; fiber-based resins, suchas cellulose acetate butyrate; and vinyl toluene-α-methyl styrenecopolymer resins. Among these resins, preferred are vinyl chlorideresins; and more preferred are vinyl chloride-vinyl acetate copolymerresins. The composition containing such a resin tends to further enhancethe abrasion resistance of the resulting recorded matters. These resinsmay be used alone or as a mixture of two or more thereof.

The vinyl chloride resin is not particularly limited, and examplesthereof include copolymer resins of vinyl chloride and one or moreselected from the group consisting of vinyl acetate, vinylidenechloride, acryls, maleic acid, and vinyl alcohol. Among these resins,preferred are vinyl chloride-vinyl acetate copolymer resins composed ofvinyl chloride and vinyl acetate; and more preferred are vinylchloride-vinyl acetate copolymer resins having a glass transitiontemperature of 60° C. or more and 80° C. or less. The acryl may be anycompound copolymerizable with vinyl chloride, and examples thereofinclude acrylic esters, such as methyl acrylate, ethyl acrylate,isopropyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate;methacrylic esters, such as methyl methacrylate, ethyl methacrylate,isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate,t-butyl methacrylate, cyclohexyl methacrylate, and 2-ethylhexylmethacrylate; carboxyl group-containing monomers, such as acrylic acid,methacrylic acid, maleic acid, fumaric acid, itaconic acid, mono-n-butylmaleate, mono-n-butyl fumarate, and mono-n-butyl itaconate; hydroxygroup-containing (meth)acrylates; amide group-containing monomers;glycidyl group-containing monomers; cyano group-containing monomers;hydroxy group-containing allyl compounds; tertiary aminogroup-containing monomers; and alkoxysilyl group-containing monomers.These acryls may be used alone or in combination of two or more thereof.

The amount of the resin is preferably 0.1 mass % or more and 10 mass %or less, more preferably 0.3 mass % or more and 5.0 mass % or less, andmost preferably 0.5 mass % or more and 3.0 mass % or less based on thetotal amount (100 mass %) of the composition. The composition containinga resin within such a range tends to provide further excellent abrasionresistance.

The composition of the embodiment may further include one or moreoptional components that can be used in known non-aqueous inkcompositions for ink jet, in addition to the above-mentioned components.Examples of the optional component include coloring materials such as adye, surfactants, dispersants, penetrants, moisturizing agents,dissolution aids, viscosity modifiers, pH adjusters, antioxidants,preservatives, antifungal agents, corrosion inhibitors, chelating agentsfor capturing metal ions that influence dispersion, other additives, andsolvents. These components may be each used alone or in combination.

Ink Jet Recording Method

The ink jet recording method of the embodiment includes a step ofperforming recording on a recording medium by an ink jet method usingthe non-aqueous ink jet composition described above. Specifically, animage is recorded by discharging droplets of the non-aqueous compositionand allowing the droplets to adhere to a recording medium, preferably, alow-absorbent recording medium.

In the present specification, the term “low-absorbent recording medium”refers to a recording medium that absorbs 10 mL/m² or less of waterwithin 30 msec^(1/2) from the start of contact with water when measuredby a Bristow method. Such a property may be possessed by at least therecording surface. In this definition, examples of the “low-absorbentrecording medium” in the present invention include non-absorbentrecording media that do not absorb water at all. The Bristow method ismost commonly used as a method for measuring the amount of liquidabsorbed in a short period of time and is also employed by JapanTechnical Association of the Pulp and Paper Industry (JAPAN TAPPI). Thedetails of the test method are described in Standard No. “Paper andPaperboard—Liquid Absorption Test Method—Bristow Method” in “JAPAN TAPPIPaper and Pulp Test Methods, 2000 Edition”.

Examples of the low-absorbent recording medium include sheets, films,and fiber products containing low-absorbent materials. The low-absorbentrecording medium may be composed of a base material (for example, paper,fiber, leather, plastic, glass, ceramics, or a metal) and a layercontaining a low-absorbent material (hereinafter, also referred to as“low-absorbent layer”) disposed on the surface of the base material.Examples of the low-absorbent material include, but not limited to,olefin-based resins, ester-based resins, urethane-based resins,acrylic-based resins, and vinyl chloride-based resins.

Among these media, a medium having a recording surface containing avinyl chloride-based resin can be preferably used as the low-absorbentrecording medium. Examples of the vinyl chloride-based resin includepoly(vinyl chloride), vinyl chloride-ethylene copolymers, vinylchloride-vinyl acetate copolymers, vinyl chloride-vinyl ethercopolymers, vinyl chloride-vinylidene chloride copolymers, vinylchloride-maleate copolymers, vinyl chloride-(meth)acrylic acidcopolymers, vinyl chloride-(meth)acrylate copolymers, and vinylchloride-urethane copolymers. The characteristics, such as thickness,shape, color, softening temperature, and hardness, of the low-absorbentrecording medium are not particularly limited.

The non-aqueous composition of the embodiment having the above-describedformulation can show advantageous effects, excellent intensity andabrasion resistance, against, in particular, a low-absorbent recordingmedium, specifically, a recording medium containing a vinylchloride-based resin. Accordingly, the ink jet recording methodaccording to the embodiment can record images having further excellentintensity and abrasion resistance by allowing droplets of thenon-aqueous composition to adhere to, in particular, a low-absorbentrecording medium, specifically, a recording medium containing a vinylchloride-based resin.

The ink jet recording method of the embodiment may be performed with anyink jet recording apparatus, and a drop-on-demand ink jet recordingapparatus is preferred. Examples of the drop-on-demand ink jet recordingapparatus include those employing a piezoelectric element recordingmethod using piezoelectric elements disposed in recording heads andthose employing a heat jet recording method using heat energy generatedby, for example, heaters of heat-generating resistor elements disposedin recording heads. Any recording method can be employed for the ink jetrecording apparatus. An example of the ink jet recording apparatus ofthe embodiment will now be described in more detail.

Ink Jet Recording Apparatus

The ink jet recording apparatus of the embodiment can use a known inkjet printer. For example, the ink jet printer (hereinafter, also simplyreferred to as “printer”) shown in FIG. 1 can be used.

FIG. 1 is a perspective view illustrating the configuration of a printer1 in the embodiment. As shown in FIG. 1, the printer 1 includes acarriage 4 on which an ink jet recording head 2 is mounted and an inkcartridge 3 is detachably installed; a platen 5 disposed below the inkjet recording head (ink jet head) 2 and onto which a recording medium 6is transported; a carriage-moving mechanism 7 for moving the carriage 4in the medium width direction (main scanning direction S) of therecording medium 6; and a medium-transporting mechanism 8 fortransporting the recording medium 6 in the medium-transportingdirection. The printer 1 also has a controller CONT that controls theentire operation of the printer 1.

The recording head 2 includes cavities for discharging the non-aqueouscomposition accommodated therein from nozzles; discharge-drivingportions provided to the corresponding cavities and applying drivingforce for discharge to the non-aqueous composition; and nozzles providedto the corresponding cavities and discharging the non-aqueouscomposition to the outside of the head. One head may be provided with aplurality of independent cavities and the discharge-driving portions andnozzles provided to the corresponding cavities. The discharge-drivingportion can be formed using, for example, an electromechanicaltransducer, such as a piezoelectric element, that changes the volume ofthe cavity by mechanical deformation, or an electrothermal transducerthat generates heat to form air bubbles in the non-aqueous compositionand thereby discharges the non-aqueous composition. The printer 1 mayinclude one head for one non-aqueous composition or may include aplurality of heads for one non-aqueous composition.

The ink cartridge 3 is composed of a plurality of independentcartridges, and each cartridge is filled with the non-aqueouscomposition. The cartridge filled with the non-aqueous composition maybe removed from the carriage 4 during ordinary printing, but should beinstalled on the carriage 4 at least when the flow channel of thenon-aqueous composition is rinsed.

The platen 5 includes a platen heater and is configured so as to heatthe recording medium to a preset temperature. The recording head 2 doesnot have a built-in heater, but the temperature of the recording head isalso increased as a result of heating of the recording medium, andthereby the temperature of the non-aqueous composition accommodated inthe recording head 2 tends to raise. The printer 1 may include anafter-heater (not shown) in the recording medium-transporting pathdownstream of the platen heater.

The above-described non-aqueous composition of the embodiment isdischarged from the recording head 2. Herein, the temperature of theplaten when the non-aqueous composition is discharged from the recordinghead 2 is preferably 35° C. or more and more preferably 40° C. or more,and is preferably 80° C. or less, more preferably 70° C. or less, morepreferably 60° C. or less, and most preferably 50° C. or less. Theplaten heated with a platen heater to a temperature within theabove-mentioned range is advantageous to provide higher quality torecorded matters.

In addition, in the embodiment, the frequency of discharge from therecording head 2 is preferably 1.0 kHz or more and 200 kHz or less. Adischarge frequency lower than the upper limit of the above-mentionedrange is preferred from the point of provide more excellent dischargestability, and a discharge frequency higher than the lower limit of theabove-mentioned range is preferred from the point of providing a higherrecording speed. The term “discharge frequency” indicates the frequencyof discharging each non-aqueous composition droplet as a discharge unit.The discharge frequency is preferably 2.0 kHz or more, more preferably3.0 kHz or more, more preferably 5.0 kHz or more, and most preferably 10kHz or more from the viewpoint of further accelerating the recordingspeed. In addition, the discharge frequency is preferably 200 kHz orless, more preferably 150 kHz or less, more preferably 100 kHz or less,and most preferably 50 kHz or less from the viewpoint of enhancing thedischarge stability. Furthermore, the discharge frequency is preferably20 kHz or less and more preferably 15 kHz or less from the point ofproviding further excellent discharge stability while maintaining therecording speed. At the same time, the discharge frequency is preferably15 kHz or more and more preferably 20 kHz or more from the point ofproviding higher recording speed while maintaining the dischargestability.

As an example of the printer 1 of the embodiment, a so-calledon-carriage type printer having the ink cartridge mounted on thecarriage 4 was described above, but the printer is not limited thereto.For example, the printer may be of a so-called off-carriage type, wherean ink container (such as an ink pack or ink cartridge) filled with thenon-aqueous composition is installed on, for example, the housing of theprinter 1 and the non-aqueous composition is supplied to the head 2through an ink supply tube.

The ink jet recording apparatus of the embodiment can employ an ink setincluding a plurality of non-aqueous compositions. The ink set of theembodiment may include a plurality of the non-aqueous ink jetcompositions of the embodiment and may further include one or morenon-aqueous compositions (other non-aqueous composition(s)) differentfrom the non-aqueous ink jet compositions of the embodiment. In such acase, the ink set may include a magenta ink of the non-aqueouscomposition of the embodiment and a yellow ink and a cyan ink of theother non-aqueous compositions. Alternatively, the ink set may include ared ink of the non-aqueous composition of the embodiment and a magentaink, a yellow ink, and a cyan ink of the other non-aqueous compositions.From the viewpoint of achieving more excellent color reproducibility,the non-aqueous composition of the embodiment is preferably used as ared ink and is preferably used together with magenta, yellow, and cyaninks of the other non-aqueous compositions.

A second aspect (hereinafter, referred to as “the embodiment”) forimplementing the present invention will now be described in detail withreference to the drawing as needed. The following embodiment isexemplification for explaining the present invention and is not intendedto limit the present invention to the following contents. The presentinvention can be implemented by being appropriately modified within thescope of the gist. In the drawing, the same elements are denoted by thesame reference signs, and the duplicated explanation is omitted. Thepositional relation such as up and down and right and left is based onthe positional relation shown in the drawing, unless otherwisespecified. The dimensional ratio is not limited to that shown in thedrawing.

Non-Aqueous Ink Jet Composition

The non-aqueous ink jet composition (hereinafter, also simply referredto as “ink jet composition”, “non-aqueous composition”, or“composition”) of the embodiment includes a pigment component containinga diketopyrrolopyrrole pigment and an organic solvent. The organicsolvent contains a glycol ether. The pigment has an average particlediameter of 100 nm or more and 240 nm or less.

The composition of the embodiment includes a pigment componentcontaining a diketopyrrolopyrrole pigment and also the glycol ether. Thepigment has an average particle diameter of 100 nm or more and 240 nm orless. As a result, the resulting recorded matters have excellentintensity, and the composition has excellent storage stability. Thefactors thereof are presumed (but not limited to) as follows. Knownnon-aqueous compositions containing pigments having an average particlediameter higher than 240 nm can improve the intensity of the resultingrecorded matters. However, excellent discharge stability cannot beobtained mainly due to the pigments having an average particle diameterhigher than 240 nm. In contrast, the non-aqueous composition of theembodiment enhances the color developing property of the pigment itselfby employing a diketopyrrolopyrrole pigment and prevents occurrence ofuneven aggregation in the resulting recorded matters by containing theglycol ether. As a result, even if the pigment used has an averageparticle diameter is 240 nm or less, the resulting recorded matters havesufficiently excellent intensity. In addition, excellent dischargestability can be achieved mainly due to the average particle diameter of240 nm or less of the pigment.

In the embodiment, the term “non-aqueous composition” refers to acomposition of which the main solvent is of other than water, such as anorganic solvent. Herein, the term “main solvent” indicates that theamount of the solvent in a composition is 50 mass % or more, preferably70 mass % or more, and more preferably 90 mass % or more based on 100mass % of the composition. In addition, it is preferable that water isnot intentionally added to a composition as a main solvent component inpreparation of the composition, and it is preferable that water isinevitably contained in a composition as an impurity. The amount ofwater in the composition is preferably 3.0 mass % or less, morepreferably 2.0 mass % or less, more preferably 1.0 mass % or less, andmost preferably 0.5 mass % or less based on 100 mass % of thecomposition. The lower limit of the water content is not particularlylimited and may be lower than the detection limit or may be 0.01 mass %.

The amount of water in the composition can be controlled by, forexample, removing water from each component of the composition,specifically, removing water contaminating the organic solvent; removingwater from the composition; or preventing water from contaminating thecomposition during preparation of the composition. Among these methods,the method removing water contaminating the organic solvent is morespecifically performed by purifying the organic solvent by distillation;applying the organic solvent to a semi-permeable membrane thatselectively allows water to permeate; or selectively allowing watercontaminating the organic solvent to adsorb to a water adsorbent. Amongthese methods, from the viewpoint of more efficiently and certainlyreducing the amount of water, purification by distillation is preferred.

The non-aqueous ink jet composition of the embodiment includes a pigmentand an organic solvent described below. Compositions containing solventsare roughly classified into two: a real-solvent (high organic solvent)composition and an eco-solvent (low organic solvent) composition. Theeco-solvent composition is a low-odor and human and environment-friendlycomposition, and the organic solvent contained in the composition doesnot fall under the category of organic solvents defined by theIndustrial Safety and Health Act, does not fall under the categories ofClass-1 and Class-2 organic solvents defined by the Ordinance OnPrevention of Organic Solvent Poisoning, and does not fall under thecategory of organic solvents requiring local exhaust ventilation inindoor workplaces defined as the installation environment by the FireService Act. Although the non-aqueous composition of the embodiment maycontain an organic solvent that can be used in real-solvent compositionsor an organic solvent that can be used in eco-solvent compositions,preferred is an organic solvent that can be used in eco-solventcompositions.

The “ink jet composition” in the embodiment can be used in a variety ofpurposes as a composition to be discharged by an ink jet method, and thepurposes are not limited. Specifically, the composition is used, forexample, as a composition for inks. The composition of the embodimentwill now be described in more detail with a case of being used as an inkcomposition for ink jet recording (hereinafter, also simply referred toas “ink composition”), which in one embodiment of ink jet compositions,but the composition of the embodiment is not limited thereto.

Pigment

The pigment of the embodiment may contain any pigment as long as adiketopyrrolopyrrole pigment is contained, and may contain only adiketopyrrolopyrrole pigment or may contain a mixture of adiketopyrrolopyrrole pigment and a pigment other than thediketopyrrolopyrrole pigment (hereinafter, also referred to as “otherpigment”).

The diketopyrrolopyrrole pigment may be any pigment having adiketopyrrolopyrrole skeleton. The diketopyrrolopyrrole skeleton mayinclude a substituent, such as an alkyl group, or may include nosubstituent (the case that the substituents are all hydrogen atoms).Examples of the diketopyrrolopyrrole pigment include, but not limitedto, red organic pigments, such as C.I. Pigment Red 254, C.I. Pigment Red255, C.I. Pigment Red 264, C.I. Pigment Red 270, and C.I. Pigment Red272; and orange organic pigments, such as C.I. Pigment Orange 71, C.I.Pigment Orange 73, and C.I. Pigment Orange 81. Among these pigments,from the viewpoint of forming recorded matters having more excellentintensity, preferred are the red organic pigments: C.I. Pigment Red 254,C.I. Pigment Red 255, and C.I. Pigment Red 264; more preferred are C.I.Pigment Red 254 and C.I. Pigment Red 255; and most preferred is C.I.Pigment Red 254. These diketopyrrolopyrrole pigments may be used aloneor as a mixture of two or more thereof.

The diketopyrrolopyrrole pigment is preferably a diketopyrrolopyrrolered pigment. The diketopyrrolopyrrole red pigment exhibits a red colorand has a diketopyrrolopyrrole skeleton, and examples thereof includediketopyrrolopyrrole red pigments mentioned above as red pigments.Herein, the term “exhibiting a red color” indicates that when the colorof a recorded matter formed by applying an ink jet composition to awhite recording medium so as to cover the entire surface is measured bycolorimetry using Spectrolino (manufactured by GretagMacbeth), the valueh in the L*C*h color space of the CIE standard colorimetric system is−30° to 45°, preferably −30° to 32°, more preferably −30° to 30°, andmost preferably −30° to 25°.

The amount of the diketopyrrolopyrrole pigment is not particularlylimited and is 30 mass % or more and 100 mass % or less, 50 mass % ormore and 100 mass % or less, or 70 mass % or more and 100 mass % or lessbased on the total amount (100 mass %) of the pigment component. The useof a composition containing the diketopyrrolopyrrole pigment in anamount within such a range tends to provide more excellent intensity.

The pigment has an average particle diameter of 100 nm or more and 240nm or less, preferably 120 nm or more and 230 nm or less, and morepreferably 150 nm or more and 220 nm or less. The pigment having anaverage particle diameter of 100 nm or more provides excellent intensityto the resulting recorded matters and excellent weather resistance. Thepigment having an average particle diameter of 240 nm or less enhancesthe dispersion stability of the diketopyrrolopyrrole pigment andprovides excellent discharge stability. The pigment having an averageparticle diameter within such a range may be prepared by any method. Forexample, a commercially available pigment of which the particle diameterhas been adjusted may be prepared; the average particle diameter may beadjusted within the above-mentioned range by mixing a plurality ofpigments having different particle diameters; or a commerciallyavailable diketopyrrolopyrrole pigment is mixed with a solvent, and themixture is then appropriately pulverized with, for example, a ball mill,bead mill, ultrasonic waves, or a jet mill to give a desired averageparticle diameter or particle diameter distribution. Further, as anothermethod for adjusting the average particle diameter, a process involvingpreparation of a pigment having a small diameter as a primary particleand preparation of a dispersion of the pigment in a solvent by mixingthe pigment with (a part or the whole of) the solvent while changing theamount of a dispersant can be employed. That is, use of a large amountof a dispersant prevents aggregation of the primary particles to allowdispersing at a particle diameter similar to that of the primaryparticles, resulting in a small average particle diameter determined onthe basis of the diameter of the primary particles. In contrast, use ofa small amount of a dispersant aggregates the primary particles,resulting in an average particle diameter determined on the basis of theparticle diameter of secondary particles. In this process, a pigmenthaving a smaller primary particle has a higher degree of freedom incontrol of the average particle diameter. Furthermore, in order toincrease the degree of freedom in control of the average particlediameter, the prepared pigment may be pulverized with, for example, aball mill to have a smaller diameter and then may be subjected tocontrol of the average particle diameter using a dispersant. The averageparticle diameter is measured by, for example, laser microscopy or acoulter counter method. Herein, the term “average particle diameter”refers to volume average particle diameter.

The other pigment may be any pigment other than the diketopyrrolopyrrolepigment and can be, for example, inorganic pigments and organic pigmentsthat are usually contained in known non-aqueous ink compositions. Theseother pigments may be used alone or as a mixture of two or more thereof.

Examples of the organic pigment include, but not limited to, azopigments (e.g., azo lake, insoluble azo pigments, condensed azopigments, and chelate azo pigments), polycyclic pigments (e.g.,phthalocyanine pigments, perylene and perylene pigments, anthraquinonepigments, quinacridone pigments, dioxadine pigments, thioindigopigments, isoindolinone pigments, and quinophthalone pigments), dyelakes (e.g., basic dye lakes and acid dye lakes), nitro pigments,nitroso pigments, aniline black, and daylight fluorescent pigments.

Examples of the inorganic pigment include, but not limited to, carbonblack, titanium dioxide, silica, and alumina.

It is also preferred to use a red organic pigment (hereinafter, alsoreferred to as “other red organic pigment”) other than thediketopyrrolopyrrole pigment or an orange organic pigment (hereinafter,also referred to as “other orange organic pigment”) other than thediketopyrrolopyrrole pigment, as the other pigment, from the viewpointof discharge stability and abrasion resistance.

Examples of the other red organic pigment include, but not limited to,C.I. Pigment Red 2, C.I. Pigment Red 3, C.I. Pigment Red 5, C.I. PigmentRed 6, C.I. Pigment Red 7, C.I. Pigment Red 15, C.I. Pigment Red 16,C.I. Pigment Red 48:1, C.I. Pigment Red 53:1, C.I. Pigment Red 57:1,C.I. Pigment Red 122, C.I. Pigment Red 123, C.I. Pigment Red 139, C.I.Pigment Red 144, C.I. Pigment Red 149, C.I. Pigment Red 166, C.I.Pigment Red 170, C.I. Pigment Red 177, C.I. Pigment Red 178, C.I.Pigment Red 179, C.I. Pigment Red 194, C.I. Pigment Red 209, C.I.Pigment Red 222, and C.I. Pigment Red 224.

The other orange organic pigment is not particularly limited, andexamples thereof include C.I. Pigment Orange 31, C.I. Pigment Orange 43,and C.I. Pigment Orange 64.

The amount of the pigment component is preferably 0.5 mass % or more and10 mass % or less, more preferably 1.0 mass % or more and 5.0 mass % orless, more preferably 2.0 mass % or more and 4.0 mass % or less, andmost preferably 2.5 mass % or more and 3.0 mass % or less, based on thetotal amount (100 mass %) of the composition. A pigment componentcontent of 0.5 mass % or more tends to provide more excellent intensityand weather resistance to the resulting recorded matters, and a pigmentcomponent content of 10 mass % or less tends to provide more excellentweather resistance to the resulting recorded matters and have excellentdischarge stability.

Organic Solvent

The organic solvent of the embodiment contains a glycol ether. Inparticular, the organic solvent containing a glycol diether representedby Formula (1) (hereinafter, also referred to as “specific glycoldiether”) improves the dispersion stability of the diketopyrrolopyrrolepigment to improve the discharge stability. The organic solventcontaining a glycol monoether represented by Formula (2) (hereinafter,also referred to as “specific glycol monoether”) improves thewet-spreading property of an ink containing a diketopyrrolopyrrolepigment and tends to provide better intensity.

The organic solvent preferably contains a glycol diether represented byFormula (1) and a glycol monoether represented by Formula (2) andpreferably contains the glycol diether represented by Formula (1) in anamount higher than 50 mass % based on the total amount (100 mass %) ofthe glycol diether represented by Formula (1) and the glycol monoetherrepresented by Formula (2). The non-aqueous composition having such aformulation has good dispersion stability and good discharge stability.In addition, the resulting recorded matters have high abrasionresistance.R¹O—(R³O)_(m)—R²  (1)where, R¹ and R² each independently represent an alkyl group having 1 to7 carbon atoms, R³ represents an alkylene group having 1 to 3 carbonatoms, and m represents an integer of 1 to 7,OH—(R⁵O)_(n)—R⁴  (2)where, R⁴ represents an alkyl group having 1 to 7 carbon atoms, R⁵represents an alkylene group having 1 to 3 carbon atoms, and nrepresents an integer of 1 to 7.

In Formula (1), R¹ and R² each independently preferably represent analkyl group having 1 to 5 carbon atoms; R³ preferably represents analkylene group having 2 or 3 carbon atoms; and m preferably representsan integer of 1 to 6. In Formula (2), R⁴ preferably represents an alkylgroup having 1 to 5 carbon atoms; R⁵ preferably represents an alkylenegroup having 2 or 3 carbon atoms; and n preferably represents an integerof 1 to 6.

Examples of the specific glycol diether include, but not limited to,ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethyleneglycol dibutyl ether, diethylene glycol dimethyl ether, diethyleneglycol diethyl ether, diethylene glycol ethyl methyl ether, diethyleneglycol dibutyl ether, triethylene glycol dimethyl ether, triethyleneglycol diethyl ether, triethylene glycol dibutyl ether, tetraethyleneglycol dimethyl ether, tetraethylene glycol diethyl ether, tetraethyleneglycol dibutyl ether, propylene glycol dimethyl ether, propylene glycoldiethyl ether, dipropylene glycol dimethyl ether, and dipropylene glycoldiethyl ether. Among these glycol diethers, preferred are diethyleneglycol ethyl methyl ether, diethylene glycol diethyl ether, andtetraethylene glycol dimethyl ether; and more preferred is diethyleneglycol ethyl methyl ether. The composition containing such a preferredspecific glycol diether tends to provide more excellent abrasionresistance to the resulting recorded matters and tends to have moreexcellent discharge stability. These specific glycol diethers may beused alone or in combination of two or more thereof.

Among the specific glycol diethers, more preferred are glycol diethershaving a flash point of 100° C. or less, more preferably 90° C. or less,and more preferably 80° C. or less. The composition including a specificglycol diether having a flash point of 100° C. or less tends to provideexcellent drying properties and more excellent abrasion resistance tothe resulting recorded matters.

The amount of the specific glycol diether is preferably 5.0 mass % ormore and 90 mass % or less, more preferably 20 mass % or more and 80mass % or less, and most preferably 30 mass % or more and 70 mass % orless based on the total amount (100 mass %) of the composition. Thecomposition containing the specific glycol diether within theabove-mentioned range tends to provide more excellent intensity to theresulting recorded matters. Herein, the amount of the specific glycoldiether in the composition is the amount including the amount of thespecific glycol diether contained in, for example, a dispersion.

Examples of the specific glycol monoether include, but not limited to,ethylene glycol monomethyl ether, ethylene glycol monoethyl ether,ethylene glycol mono-n-propyl ether, ethylene glycol monoisopropylether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether,ethylene glycol monophenyl ether, diethylene glycol monomethyl ether,diethylene glycol monoethyl ether, diethylene glycol monobutyl ether,triethylene glycol monomethyl ether, triethylene glycol monoethyl ether,triethylene glycol monobutyl ether, tetraethylene glycol monomethylether, tetraethylene glycol monoethyl ether, tetraethylene glycolmonobutyl ether, propylene glycol monomethyl ether, propylene glycolmonoethyl ether, dipropylene glycol monomethyl ether, and dipropyleneglycol monoethyl ether. Among these glycol monoethers, preferred areethylene glycol monobutyl ether, triethylene glycol monobutyl ether,tetraethylene glycol monobutyl ether, and dipropylene glycol monoethylether; and more preferred is triethylene glycol monobutyl ether. Thecomposition containing such a preferred specific glycol monoether tendsto provide more excellent abrasion resistance to the resulting recordedmatters and have more excellent discharge stability. These specificglycol monoethers may be used alone or in combination of two or morethereof.

Among the specific glycol monoethers, more preferred are glycolmonoethers having a flash point of 150° C. or less, more preferably 100°C. or less, more preferably 90° C. or less, and more preferably 80° C.or less. The composition including a specific glycol monoether having aflash point of 150° C. or less tends to provide excellent dryingproperties and more excellent abrasion resistance to the resultingrecorded matters.

The amount of the specific glycol monoether is preferably 5.0 mass % ormore and 80 mass % or less, more preferably 10 mass % or more and 60mass % or less, and most preferably 15 mass % or more and 40 mass % orless based on the total amount (100 mass %) of the composition. Thecomposition containing the specific glycol monoether within theabove-mentioned range tends to provide more excellent intensity to theresulting recorded matters. Herein, the amount of the specific glycolmonoether in the composition is the amount including the amount of thespecific glycol monoether contained in, for example, a dispersion.

The total amount of the specific glycol diether and the specific glycolmonoether is preferably 30 mass % or more and 99.5 mass % or less, morepreferably 40 mass % or more and 95 mass % or less, and most preferably50 mass % or more and 80 mass % or less based on the total amount (100mass %) of the composition. The composition containing the specificglycol diether and the specific glycol monoether within theabove-mentioned range tends to provide more excellent intensity to theresulting recorded matters. Herein, the total amount of the specificglycol diether and the specific glycol monoether in the composition isthe amount including the amounts of the specific glycol diether and thespecific glycol monoether contained in, for example, a dispersion.

The organic solvent may further contain a glycol diether (hereinafter,also referred to as “other glycol diether”) other than the specificglycol diether and/or a glycol monoether (hereinafter, also referred toas “other glycol monoether”) other than the specific glycol monoether.Examples of the other glycol diether include heptaethylene glycoldimethyl ether. Examples of the other glycol monoether includeheptaethylene glycol monomethyl ether.

The organic solvent further containing a cyclic lactone tends to providemore excellent abrasion resistance to the resulting recorded matters.The cyclic lactone may be any compound having a ring structure formed byester bonds, and examples thereof include γ-lactone having afive-membered ring structure, δ-lactone having a six-membered ringstructure, and ε-lactone having a seven-membered ring structure.Examples of the cyclic lactone include, but not limited to,γ-butyrolactone, γ-valerolactone, γ-hexalactone, γ-heptalactone,γ-octalactone, γ-nonalactone, γ-decalactone, γ-undecalactone,δ-valerolactone, δ-hexalactone, δ-heptalactone, δ-octalactone,δ-nonalactone, δ-decalactone, δ-undecalactone, and ε-caprolactam. Amongthese cyclic lactones, preferred are γ-lactone having a five-memberedring structure and δ-lactone having a six-membered ring structure; morepreferred are γ-butyrolactone, γ-valerolactone, and δ-valerolactone; andmost preferred is γ-butyrolactone. The composition containing such acyclic lactone tends to provide further enhanced abrasion resistance.The cyclic lactones may be used alone or in combination of two or morethereof.

The amount of the cyclic lactone is preferably 1.0 mass % or more and 50mass % or less, more preferably 3.0 mass % or more and 40 mass % orless, and most preferably 5.0 mass % or more and 30 mass % or less basedon the total amount (100 mass %) of the composition. A cyclic lactonecontent of 1.0 mass % or more tends to provide more excellent abrasionresistance, and a cyclic lactone content of 50 mass % or less tends toprovide more excellent intensity. Herein, the amount of the cycliclactone in the composition is the amount including the amount of thecyclic lactone contained in, for example, a dispersion.

The amount of the organic solvent is preferably 35 mass % or more and 95mass % or less, more preferably 50 mass % or more and 90 mass % or less,and most preferably 60 mass % or more and 90 mass % or less based on thetotal amount (100 mass %) of the composition. Herein, the amount of theorganic solvent in the composition is the amount including the amount ofthe organic solvent contained in, for example, a dispersion.

Resin

The composition of the embodiment may further includes a resin formainly adjusting the viscosity of the composition. Examples of the resininclude, but not limited to, acrylic resins; styrene acrylic resins;rosin-modified resins; phenolic resins; terpene-based resins; polyesterresins; polyamide resins; epoxy resins; vinyl chloride resins, such asvinyl chloride-vinyl acetate copolymer resins; fiber-based resins, suchas cellulose acetate butyrate; and vinyl toluene-α-methyl styrenecopolymer resins. Among these resins, preferred are vinyl chlorideresins; and more preferred are vinyl chloride-vinyl acetate copolymerresins. The composition containing such a resin tends to further enhancethe abrasion resistance of the resulting recorded matters. These resinsmay be used alone or as a mixture of two or more thereof.

The vinyl chloride resin is not particularly limited, and examplesthereof include copolymer resins of vinyl chloride and one or moreselected from the group consisting of vinyl acetate, vinylidenechloride, acryls, maleic acid, and vinyl alcohol. Among these copolymerresins, preferred are vinyl chloride-vinyl acetate copolymer resins ofvinyl chloride and vinyl acetate; and more preferred are vinylchloride-vinyl acetate copolymer resins having a glass transitiontemperature of 60° C. or more and 80° C. or less. The acryl may be anycompound copolymerizable with vinyl chloride, and examples thereofinclude acrylic esters, such as methyl acrylate, ethyl acrylate,isopropyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate;methacrylic esters, such as methyl methacrylate, ethyl methacrylate,isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate,t-butyl methacrylate, cyclohexyl methacrylate, and 2-ethylhexylmethacrylate; carboxyl group-containing monomers, such as acrylic acid,methacrylic acid, maleic acid, fumaric acid, itaconic acid, mono-n-butylmaleate, mono-n-butyl fumarate, and mono-n-butyl itaconate; hydroxygroup-containing (meth)acrylates; amide group-containing monomers;glycidyl group-containing monomers; cyano group-containing monomers;hydroxy group-containing allyl compounds; tertiary aminogroup-containing monomers; and alkoxysilyl group-containing monomers.These acryls may be used alone or in combination of two or more thereof.

The amount of the resin is preferably 0.1 mass % or more and 10 mass %or less, more preferably 0.3 mass % or more and 5.0 mass % or less, andmost preferably 0.5 mass % or more and 3.0 mass % or less based on thetotal amount (100 mass %) of the composition. The composition containinga resin within such an amount tends to provide further excellentabrasion resistance.

The composition of the embodiment may further include one or moreoptional components that can be used in known non-aqueous inkcompositions for ink jet, in addition to the above-mentioned components.Examples of the optional component include coloring materials such as adye, surfactants, dispersants, penetrants, moisturizing agents,dissolution aids, viscosity modifiers, pH adjusters, antioxidants,preservatives, antifungal agents, corrosion inhibitors, chelating agentsfor capturing metal ions that influence dispersion, other additives, andsolvents. These components may be each used alone or in combination.

Ink Jet Recording Method

The ink jet recording method of the embodiment includes a process ofcarrying out recording on a recording medium by an ink jet method usingthe above-described non-aqueous composition. Specifically, an image isrecorded by discharging droplets of the non-aqueous composition andallowing the droplets to adhere to a recording medium, preferably, alow-absorbent recording medium.

In the present specification, the term “low-absorbent recording medium”refers to a recording medium that absorbs 10 mL/m² or less of waterwithin 30 msec^(1/2) from the start of contact with water when measuredby a Bristow method. Such a property may be possessed by at least therecording surface. In this definition, examples of the “low-absorbentrecording medium” in the present invention include non-absorbentrecording media that do not absorb water at all. The Bristow method ismost commonly used as a method for measuring the amount of liquidabsorbed in a short period of time and is also employed by JapanTechnical Association of the Pulp and Paper Industry (JAPAN TAPPI). Thedetails of the test method are described in Standard No. “Paper andPaperboard—Liquid Absorption Test Method—Bristow Method” in “JAPAN TAPPIPaper and Pulp Test Methods, 2000 Edition”.

Examples of the low-absorbent recording medium include sheets, films,and fiber products containing low-absorbent materials. The low-absorbentrecording medium may be composed of a base material (for example, paper,fiber, leather, plastic, glass, ceramics, or a metal) and a layercontaining a low-absorbent material (hereinafter, also referred to as“low-absorbent layer”) disposed on the surface of the base material.Examples of the low-absorbent material include, but not limited to,olefin-based resins, ester resins, urethane-based resins, acrylic-basedresins, and vinyl chloride-based resins.

Among these media, a medium having a recording surface containing avinyl chloride-based resin can be preferably used as the low-absorbentrecording medium. Examples of the vinyl chloride-based resin includepoly(vinyl chloride), vinyl chloride-ethylene copolymers, vinylchloride-vinyl acetate copolymers, vinyl chloride-vinyl ethercopolymers, vinyl chloride-vinylidene chloride copolymers, vinylchloride-maleate copolymers, vinyl chloride-(meth)acrylic acidcopolymers, vinyl chloride-(meth)acrylate copolymers, and vinylchloride-urethane copolymers. The characteristics, such as thickness,shape, color, softening temperature, and hardness, of the low-absorbentrecording medium are not particularly limited.

The non-aqueous composition of the embodiment having the above-describedformulation can show advantageous effects, excellent intensity andabrasion resistance, against, in particular, a low-absorbent recordingmedium, specifically, a recording medium containing a vinylchloride-based resin. Accordingly, the ink jet recording methodaccording to the embodiment can record images having further excellentintensity and abrasion resistance by allowing droplets of thenon-aqueous composition to adhere to, in particular, a low-absorbentrecording medium, specifically, a recording medium containing a vinylchloride-based resin.

The ink jet recording method of the embodiment may be performed with anyink jet recording apparatus, and preferred is a drop-on-demand ink jetrecording apparatus. Examples of the drop-on-demand ink jet recordingapparatus include those employing a piezoelectric element recordingmethod using piezoelectric elements disposed in recording heads andthose employing a heat jet recording method using heat energy generatedby, for example, heaters of heat-generating resistor elements disposedin recording heads. Any recording method can be employed for the ink jetrecording apparatus. An example of the ink jet recording apparatus ofthe embodiment will now be described in more detail.

Ink Jet Recording Apparatus

The ink jet recording apparatus of the embodiment can use a known inkjet printer. For example, the ink jet printer (hereinafter, also simplyreferred to as “printer”) shown in FIG. 1 can be used.

FIG. 1 is a perspective view illustrating the configuration of a printer1 in the embodiment. As shown in FIG. 1, the printer 1 includes acarriage 4 on which an ink jet recording head 2 is mounted and an inkcartridge 3 is detachably installed; a platen 5 disposed below the inkjet recording head (ink jet head) 2 and onto which a recording medium 6is transported; a carriage-moving mechanism 7 for moving the carriage 4in the medium width direction (main scanning direction S) of therecording medium 6; and a medium-transporting mechanism 8 fortransporting the recording medium 6 in the medium-transportingdirection. The printer 1 also has a controller CONT that controls theentire operation of the printer 1.

The recording head 2 includes cavities for discharging the non-aqueouscomposition accommodated therein from nozzles; discharge-drivingportions provided to the corresponding cavities and applying drivingforce for discharge to the non-aqueous composition; and nozzles providedto the corresponding cavities and discharging the non-aqueouscomposition to the outside of the head. One head may be provided with aplurality of independent cavities and the discharge-driving portions andnozzles provided to the corresponding cavities. The discharge-drivingportion can be formed using, for example, an electromechanicaltransducer, such as a piezoelectric element, that changes the volume ofthe cavity by mechanical deformation, or an electrothermal transducerthat generates heat to form air bubbles in the non-aqueous compositionand thereby discharges the non-aqueous composition. The printer 1 mayinclude one head for one non-aqueous composition or may include aplurality of heads for one non-aqueous composition.

The ink cartridge 3 is composed of a plurality of independentcartridges, and each cartridge is filled with the non-aqueouscomposition. The cartridge filled with the non-aqueous composition maybe removed from the carriage 4 during ordinary printing, but should beinstalled on the carriage 4 at least when the flow channel of thenon-aqueous composition is rinsed.

The platen 5 includes a platen heater and is configured so as to heatthe recording medium to a preset temperature. The recording head 2 doesnot have a built-in heater, but the temperature of the recording head isalso increased as a result of heating of the recording medium, andthereby the temperature of the non-aqueous composition accommodated inthe recording head 2 tends to raise. The printer 1 may include anafter-heater (not shown) in the recording medium-transporting pathdownstream of the platen heater.

The above-described non-aqueous composition of the embodiment isdischarged from the recording head 2. Herein, the temperature of theplaten when the non-aqueous composition is discharged from the recordinghead 2 is preferably 35° C. or more and more preferably 40° C. or more,and is preferably 80° C. or less, more preferably 70° C. or less, morepreferably 60° C. or less, and most preferably 50° C. or less. Theplaten heated with a platen heater to a temperature within theabove-mentioned range is advantageous to provide higher quality torecorded matters.

In addition, in the embodiment, the frequency of discharge from therecording head 2 is preferably 1.0 kHz or more and 200 kHz or less. Adischarge frequency lower than the upper limit of the above-mentionedrange is preferred to provide more excellent discharge stability, and adischarge frequency higher than the lower limit of the above-mentionedrange is preferred to provide a higher recording speed. The term“discharge frequency” means the frequency of discharging eachnon-aqueous composition droplet as a discharge unit. The dischargefrequency is preferably 2.0 kHz or more, more preferably 3.0 kHz ormore, more preferably 5.0 kHz or more, and most preferably 10 kHz ormore from the viewpoint of further accelerating the recording speed. Inaddition, the discharge frequency is preferably 200 kHz or less, morepreferably 150 kHz or less, more preferably 100 kHz or less, and mostpreferably 50 kHz or less from the viewpoint of enhancing the dischargestability. Furthermore, the discharge frequency is preferably 20 kHz orless and more preferably 15 kHz or less from the viewpoint of providingfurther excellent discharge stability while maintaining the recordingspeed. At the same time, the discharge frequency is preferably 15 kHz ormore and more preferably 20 kHz or more from the viewpoint of providinghigher recording speed while maintaining the discharge stability.

As an example of the printer 1 of the embodiment, a so-calledon-carriage type printer having the ink cartridge mounted on thecarriage 4 was described above, but the printer is not limited thereto.For example, the printer may be of a so-called off-carriage type, wherean ink container (such as an ink pack or ink cartridge) filled with thenon-aqueous composition is installed on, for example, the housing of theprinter 1 and the non-aqueous composition is supplied to the head 2through an ink supply tube.

The ink jet recording apparatus of the embodiment can employ an ink setincluding a plurality of non-aqueous compositions. The ink set of theembodiment may include a plurality of the non-aqueous ink jetcompositions of the embodiment or may further include one or morenon-aqueous compositions (other non-aqueous composition(s)) differentfrom the non-aqueous ink jet compositions of the embodiment. In such acase, the ink set may include a magenta ink of the non-aqueouscomposition of the embodiment and a yellow ink and a cyan ink of theother non-aqueous compositions. Alternatively, the ink set may include ared ink of the non-aqueous composition of the embodiment and a magentaink, a yellow ink, and a cyan ink of the other non-aqueous compositions.From the viewpoint of achieving more excellent color reproducibility,the non-aqueous composition of the embodiment is preferably used as ared ink, and the other non-aqueous compositions are preferably used asmagenta, yellow, and cyan inks.

EXAMPLES

The first embodiment will now be more specifically described withreference to Examples, Comparative Examples, and Reference Examples, butthe embodiment is not limited to the following Examples within the scopeof the present invention.

The main materials for the non-aqueous compositions used in Examples,Comparative Examples, and Reference Examples are as follows:

Materials for Non-aqueous Composition

Pigment

-   -   C.I. Pigment Red 254 (PR-254) (manufactured by Tokyo Chemical        Industry Co., Ltd., trade name: Pigment Red 254)    -   C.I. Pigment Red 177 (PR-177) (manufactured by Hangzhou Xcolor        Chemical Company, trade name: Pigment Red 177)    -   C.I. Pigment Red 179 (PR-179) (manufactured by Gaoyou Auxiliary        Factory, trade name: Pigment Red 179)    -   C.I. Pigment Red 224 (PR-224) (manufactured by Hangzhou Xcolor        Chemical Company, trade name: Pigment Red 224) Organic solvent    -   Diethylene glycol methyl ethyl ether (manufactured by Nippon        Nyukazai Co., Ltd., trade name: MEDG)    -   Diethylene glycol diethyl ether (manufactured by Nippon Nyukazai        Co., Ltd., trade name: DEDG)    -   Triethylene glycol monobutyl ether (manufactured by Tokyo        Chemical Industry Co., Ltd., trade name: Triethylene Glycol        Monobutyl Ether)    -   Tetraethylene glycol monobutyl ether (manufactured by KH Neochem        Co., Ltd., trade name: Butycenol 40)    -   Dipropylene glycol monomethyl ether (manufactured by Tokyo        Chemical Industry Co., Ltd., trade name: Dipropylene Glycol        Monomethyl Ether)    -   Gamma-butyrolactone (manufactured by Tokyo Chemical Industry        Co., Ltd., trade name: γ-Butyrolactone)    -   Delta-valerolactone (manufactured by Tokyo Chemical Industry        Co., Ltd., trade name: δ-Valerolactone)    -   Methyl caprylate (manufactured by Tokyo Chemical Industry Co.,        Ltd., trade name: Methyl n-Octanoate)    -   Methyl caprate (manufactured by Tokyo Chemical Industry Co.,        Ltd., trade name: Methyl Decanoate)    -   3-Methoxybutyl acetate (manufactured by Daicel Corporation,        trade name: 3-Methoxybutyl Acetate)    -   3-Methoxy-3-methyl-1-butyl acetate (manufactured by Kuraray Co.,        Ltd., trade name: Solfit AC)    -   Methyl lactate (manufactured by Tokyo Chemical Industry Co.,        Ltd., trade name: Methyl D-(+)-Lactate)    -   Ethyl lactate (manufactured by Tokyo Chemical Industry Co.,        Ltd., trade name: Ethyl L-(−)-Lactate)        Resin    -   Copolymer resin of vinyl chloride and vinyl acetate        (manufactured by Nissin Chemical Co., Ltd., trade name: Solbin        CL)        Pigment-dispersing Agent    -   Solsperse 37500 (trade name, manufactured by The Lubrizol        Corporation)        Surfactant    -   BYK-340 (trade name, manufactured by BYK Chemie Japan K.K.)        Preparation of Non-Aqueous Composition

Materials shown in Tables 1 and 2 were mixed at the ratios shown in thetables and were sufficiently stirred to give each non-aqueouscomposition. In Tables 1 and 2, the unit of the numerical valuesrelating to the materials used is mass %, and the total amount is 100mass %. The amount of dissolved nitrogen in each non-aqueous compositionwas adjusted to that shown in Table 1 or 2 by the method described inthe following paragraph “Physical property 1: Amount of dissolvednitrogen”.

Physical Property 1: Amount of Dissolved Nitrogen

A 1-L beaker containing 800 mL of any of the resulting non-aqueouscompositions was put in a commercially available vacuum deaerator(deaerator including an acrylic airtight container having a volume of200×200×300 mm and connected to a vacuum gauge and a vacuum pump) set toa vacuum gauge value of about 0.08 MPa, followed by stirring at arotation speed of 500 rpm with a 5-cm-long stirrer to adjust the amountof dissolved nitrogen. The amount of dissolved nitrogen in eachnon-aqueous composition was measured with a gas chromatograph 6890N(trade name, manufactured by Agilent Technologies, Inc.). The results ofmeasurement are shown in Tables 1 and 2. The unit of the numericalvalues is mass ppm.

TABLE 1 Example Example Example Example Example Example Example Example1 2 3 4 5 6 7 8 PR-254 3.0 3.0 3.0 3.0 3.0 3.0 3.0 3.0 PR-177 — — — — —— — — PR-179 — — — — — — — — PR-224 — — — — — — — — Diethylene glycolmethyl ethyl ether 74 74 74 — 74 24 24 24 Diethylene glycol diethylether — — — 74 — — — — Triethylene glycol monobutyl ether 10 — — 10 1010 10 10 Tetraethylene glycol monobutyl ether — 10 — — — — — —Dipropylene glycol monomethyl ether — — 10 — — — — — Gamma-butyrolactone10 10 10 10 — 10 10 10 Delta-valerolactone — — — — 10 — — — Methylcaprylate — — — — — 50 — — Methyl caprate — — — — — — 50 —3-Methoxybutyl acetate — — — — — — — 50 3-Methoxy-3-methyl-1-butylacetate — — — — — — — — Methyl lactate — — — — — — — — Ethyl lactate — —— — — — — — Solsperse 37500 1.9 1.9 1.9 1.9 1.9 1.9 1.9 1.9 BYK-340 0.10.1 0.1 0.1 0.1 0.1 0.1 0.1 Solbin CL 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0Amount of dissolved nitrogen [ppm] 50 50 50 50 50 50 50 50 Dischargestability 4 4 4 4 4 4 4 3 Intensity 4 4 3 3 3 3 3 4 Manufacturing cost 33 3 3 3 3 3 3 Example Example Example Example Example Example Example 910 11 12 13 14 15 PR-254 3.0 3.0 3.0 3.0 3.0 5.0 5.0 PR-177 — — — — — —— PR-179 — — — — — — — PR-224 — — — — — — — Diethylene glycol methylethyl ether 24 24 24 74 74 72 72 Diethylene glycol diethyl ether — — — —— — — Triethylene glycol monobutyl ether 10 10 10 10 10 10 10Tetraethylene glycol monobutyl ether — — — — — — — Dipropylene glycolmonomethyl ether — — — — — — — Gamma-butyrolactone 10 10 10 10 10 10 10Delta-valerolactone — — — — — — — Methyl caprylate — — — — — — — Methylcaprate — — — — — — — 3-Methoxybutyl acetate — — — — — — —3-Methoxy-3-methyl-1-butyl acetate 50 — — — — — — Methyl lactate — 50 —— — — — Ethyl lactate — — 50 — — — — Solsperse 37500 1.9 1.9 1.9 1.9 1.91.9 1.9 BYK-340 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Solbin CL 1.0 1.0 1.0 1.01.0 1.0 1.0 Amount of dissolved nitrogen [ppm] 50 50 50 90 20 20 50Discharge stability 3 4 4 3 4 3 3 Intensity 4 3 3 3 4 4 4 Manufacturingcost 3 3 3 4 2 2 3

TABLE 2 Comparative Comparative Comparative Comparative ComparativeComparative Comparative Example Example Example Example Example ExampleExample 1 2 3 4 5 6 7 PR-254 — — — — — — — PR-177 3.0 — — 5.0 — — —PR-179 — 3.0 — — 6.0 — 6.0 PR-224 — — 3.0 — — 5.0 — Diethylene glycolmethyl ethyl ether 74 74 74 72 71 72 71 Diethylene glycol diethyl ether— — — — — — — Triethylene glycol monobutyl ether 10 10 10 10 10 10 10Tetraethylene glycol monobutyl ether — — — — — — — Dipropylene glycolmonomethyl ether — — — — — — — Gamma-butyrolactone 10 10 10 10 10 10 10Delta-valerolactone — — — — — — — Methyl caprylate — — — — — — — Methylcaprate — — — — — — — 3-Methoxybutyl acetate — — — — — — —3-Methoxy-3-methyl-1-butyl acetate — — — — — — — Methyl lactate — — — —— — — Ethyl lactate — — — — — — — Solsperse 37500 1.9 1.9 1.9 1.9 1.91.9 1.9 BYK-340 0.1 0.1 0.1 0.1 0.1 0.1 0.1 Solbin CL 1.0 1.0 1.0 1.01.0 1.0 1.0 Amount of dissolved nitrogen [ppm] 50 50 50 50 50 50 10Discharge stability 3 3 3 2 1 2 2 Intensity 2 1 2 3 3 3 3 Manufacturingcost 2 2 2 2 2 2 1 Comparative Reference Reference Reference ComparativeComparative Example Example Example Example Example Example 8 1 2 3 9 10PR-254 3.0 — — 3.0 — — PR-177 — 5.0 — — 3.0 3.0 PR-179 — — — — — —PR-224 — — 5.0 — — — Diethylene glycol methyl ethyl ether 74 72 72 74 7474 Diethylene glycol diethyl ether — — — — — — Triethylene glycolmonobutyl ether 10 10 10 10 10 10 Tetraethylene glycol monobutyl ether —— — — — — Dipropylene glycol monomethyl ether — — — — — —Gamma-butyrolactone 10 10 10 10 10 10 Delta-valerolactone — — — — — —Methyl caprylate — — — — — — Methyl caprate — — — — — — 3-Methoxybutylacetate — — — — — — 3-Methoxy-3-methyl-1-butyl acetate — — — — — —Methyl lactate — — — — — — Ethyl lactate — — — — — — Solsperse 37500 1.91.9 1.9 1.9 1.9 1.9 BYK-340 0.1 0.1 0.1 0.1 0.1 0.1 Solbin CL 1.0 1.01.0 1 1 1.0 Amount of dissolved nitrogen [ppm] 100 10 10 10 10 20Discharge stability 1 3 3 4 3 3 Intensity 2 3 3 4 2 2 Manufacturing cost4 1 1 1 1 1Formation of Recorded Matter

A PVC medium (manufactured by 3M Company, Model No. IJ180-10) as arecording medium was placed in an ink jet printer (manufactured by SeikoEpson Corporation, trade name: SC-530650); any of the compositionsprepared in Examples, Comparative Examples, and Reference Examples wasloaded into the discharge head; the temperature of the platen wasmaintained at 45° C. during the formation of a recorded matter and for 1minute after the formation of the recorded matter; and a solid patternwas formed at an application amount of 10 mg/inch² and a targetresolution of 720×720 dpi to give each recorded matter. Even if aninsufficient discharge part was caused by a discharge defect, thedefective portion was not compensated.

Evaluation 1: Discharge Stability

Any of the non-aqueous compositions prepared in Examples, ComparativeExamples, and Reference Examples was loaded on an ink jet printer(manufactured by Seiko Epson Corporation, trade name: SC-530650) and wasthen discharged from an ink jet head having 360 nozzles at a frequencyof 7 kHz to continuously form solid patterns (L dot, 600×600 dpi) for300 seconds on a PVC medium (manufactured by 3M Company, Model No.IJ180-10) as a recording medium, and the discharge was then stopped.This procedure was defined as one sequence. Subsequently, the procedurewas repeated ten sequences. The thus-prepared solid patterns as recordedmatters were investigated for dot omission, curved flight, andscattering of the ink. The nozzle having any of these phenomena wasdefined as a defective nozzle, and the ratio of the number of defectivenozzles to the total number of the nozzles (360 nozzles) was counted toevaluate discharge stability. The results are shown in Tables 1 and 2.

Evaluation Criteria

-   -   4: defective nozzle rate of 0%,    -   3: defective nozzle rate of higher than 0% and less than 5%,    -   2: defective nozzle rate of 5% or more and less than 10%, and    -   1: defective nozzle rate of 10% or more.        Evaluation 2: Image Quality (Intensity)

The intensity (C*) of each of the resulting recorded matters wasevaluated. Specifically, the value a* and the value b* of each recordedmatter were measured with a spectrophotometer (manufactured byGretagMacbeth, trade name: Spectrolino), and the value C* wascalculated. The intensity was evaluated based on the followingevaluation criteria. The calculated value was rounded off to the nearestwhole number. The results are shown in Tables 1 and 2.

Evaluation Criteria

-   -   4: value of 100 or more,    -   3: value C* of 90 to 99,    -   2: value C* of 80 to 89, and    -   1: value C* of 79 or less.        Evaluation 3: Manufacturing Cost

The manufacturing cost was evaluated from the deaeration time inadjustment of the amount of dissolved nitrogen in each non-aqueouscomposition based on the following evaluation criteria. The results areshown in Tables 1 and 2. Herein, the term “deaeration time” refers tothe time from the putting of each non-aqueous composition in the vacuumdeaerator to the collecting of the composition.

Evaluation Criteria

-   -   4: deaeration time of less than 10 minutes,    -   3: deaeration time of 10 minutes or more and less than 20        minutes,    -   2: deaeration time of 20 minutes or more and less than 30        minutes, and    -   1: deaeration time of 30 minutes or more.

The comparison among the results of Examples, Comparative Examples, andReference Examples shown in Tables 1 and 2 demonstrated that thenon-aqueous ink jet compositions according to the present invention canform recorded matters having excellent intensity, that the non-aqueousink jet compositions also have excellent discharge stability, and thatthe non-aqueous ink jet composition is also excellent in manufacturingcost.

The second embodiment will now be more specifically described withreference to Examples, Comparative Examples, and Reference Examples, butthe embodiment is not limited to the following Examples within the scopeof the present invention.

The main materials for the non-aqueous compositions used in Examples,Comparative Examples, and Reference Examples are as follows:

Materials for Non-aqueous Composition

Pigment

-   -   C.I. Pigment Red 254 (PR-254, average particle diameter: 170 nm)        (manufactured by Tokyo Chemical Industry Co., Ltd., trade name:        Pigment Red 254)    -   C.I. Pigment Red 177 (PR-177, average particle diameter: 175 nm)    -   C.I. Pigment Red 179 (PR-179, average particle diameter: 183 nm)    -   C.I. Pigment Red 224 (PR-224, average particle diameter: 168 nm)        Organic Solvent    -   Diethylene glycol methyl ethyl ether (manufactured by Hangzhou        Xcolor Chemical Company, trade name: Pigment Red 177)    -   Diethylene glycol diethyl ether (manufactured by Nippon Nyukazai        Co., Ltd., trade name: DEDG)    -   Tetraethylene glycol dimethyl ether (manufactured by Tokyo        Chemical Industry Co., Ltd., trade name: Tetraethylene Glycol        Dimethyl Ether)    -   Triethylene glycol monobutyl ether (manufactured by Tokyo        Chemical Industry Co., Ltd., trade name: Triethylene Glycol        Monobutyl Ether)    -   Tetraethylene glycol monobutyl ether (manufactured by KH Neochem        Co., Ltd., trade name: Butycenol 40)    -   Dipropylene glycol monomethyl ether (manufactured by Tokyo        Chemical Industry Co., Ltd., trade name: Dipropylene Glycol        Monomethyl Ether)    -   Ethylene glycol monobutyl ether (manufactured by Tokyo Chemical        Industry Co., Ltd., trade name: Ethylene Glycol Monobutyl Ether)    -   Gamma-butyrolactone (manufactured by Tokyo Chemical Industry        Co., Ltd., trade name: γ-Butyrolactone)    -   Delta-valerolactone (manufactured by Tokyo Chemical Industry        Co., Ltd., trade name: δ-Valerolactone) Resin    -   Copolymer resin of vinyl chloride and vinyl acetate        (manufactured by Nissin Chemical Co., Ltd., trade name: Solbin        CL)        Pigment-Dispersing Agent    -   Solsperse 37500 (trade name, manufactured by The Lubrizol        Corporation)        Surfactant    -   BYK-340 (trade name, manufactured by BYK Chemie Japan K.K.)        Preparation of Pigment Dispersion

Pigment Red 254 (PR-254) having a primary particle diameter of 170 nmwas prepared as a pigment. Subsequently, Solsperse 37500 (trade name,manufactured by The Lubrizol Corporation) was added to the pigment as adispersant with a change by changing the amount of the dispersant in arange of 0.1 to 20 mass % based on the pigment to prepare dispersionshaving desired volume average particle diameters. In an ink composition,the solvent of which the amount was the largest was defined as thedispersion medium of the pigment dispersion. PR-254 having a volumeaverage particle diameter smaller than the primary particle diameter waspulverized with a ball mill into PR-254 having a desired volume averageparticle diameter.

The volume average particle diameter of a pigment was measured bydiluting the resulting pigment dispersion with diethylene glycol diethylether to 1000 ppm or less and reading the value of the volume averageparticle diameter (median diameter D50) measured by a laser diffractionscattering method (with Microtrac UPA250 manufactured by Nikkiso Co.,Ltd.) under an environment of 20° C. As a result, C.I. Pigment Red 254pigments having average particle diameters of 50 nm, 85 nm, 103 nm, 238nm, 252 nm, and 310 nm were prepared.

Preparation of Non-aqueous Composition

Materials shown in Tables 3 and 4 were mixed at the compositional ratiosshown in the tables and were sufficiently stirred to prepare eachcomposition. In Tables 3 and 4, the unit of the numerical values is mass%, and the total amount is 100.0 mass %.

TABLE 3 Example Example Example Example Example Example 1 2 3 4 5 6PR-254 particle diameter: 50 nm — — — — — — PR-254 particle diameter: 85nm — — — — — — PR-254 particle diameter: 103 nm — 3.0 — 1.5 — — PR-254particle diameter: 170 nm 3.0 — — — 1.0 4.5 PR-254 particle diameter:238 nm — — 3.0 1.5 — — PR-254 particle diameter: 252 nm — — — — — —PR-254 particle diameter: 310 nm — — — — — — PR-177 particle diameter:175 nm — — — — — — PR-179 particle diameter: 183 nm — — — — — — PR-224particle diameter: 168 nm — — — — — — Diethylene glycol methyl ethylether (flash point: 64° C.) 50 50 50 50 52 48.5 Diethylene glycoldiethyl ether (flash point: 71° C.) — — — — — — Tetraethylene glycoldimethyl ether (flash point: 141° C.) — — — — — — Triethylene glycolmonobutyl ether (flash point: 143° C.) 34 34 34 34 34 34 Tetraethyleneglycol monobutyl ether — — — — — — Dipropylene glycol monomethyl ether(flash point: 79° C.) — — — — — — Ethylene glycol monobutyl ether (flashpoint: 62° C.) — — — — — — Gamma-butyrolactone 10 10 10 10 10 10Delta-valerolactone — — — — — — Solsperse 37500 1.9 1.9 1.9 1.9 1.9 1.9BYK-340 0.1 0.1 0.1 0.1 0.1 0.1 Solbin CL 1 1 1 1 1 1 Dischargestability 4 4 3 4 4 4 Intensity 4 3 5 4 3 4 Weather resistance 4 3 4 4 34 Abrasion resistance 4 4 4 4 4 3 Example Example Example ExampleExample 7 8 9 10 11 PR-254 particle diameter: 50 nm — — — — — PR-254particle diameter: 85 nm — — — — — PR-254 particle diameter: 103 nm — —— — — PR-254 particle diameter: 170 nm 10 3.0 3.0 3.0 3.0 PR-254particle diameter: 238 nm — — — — — PR-254 particle diameter: 252 nm — —— — — PR-254 particle diameter: 310 nm — — — — — PR-177 particlediameter: 175 nm — — — — — PR-179 particle diameter: 183 nm — — — — —PR-224 particle diameter: 168 nm — — — — — Diethylene glycol methylethyl ether (flash point: 64° C.) 43 — — 50 50 Diethylene glycol diethylether (flash point: 71° C.) — 50 — — — Tetraethylene glycol dimethylether (flash point: 141° C.) — — 50 — — Triethylene glycol monobutylether (flash point: 143° C.) 34 34 34 — — Tetraethylene glycol monobutylether — — — 34 — Dipropylene glycol monomethyl ether (flash point: 79°C.) — — — — 34 Ethylene glycol monobutyl ether (flash point: 62° C.) — —— — — Gamma-butyrolactone 10 10 10 10 10 Delta-valerolactone — — — — —Solsperse 37500 1.9 1.9 1.9 1.9 1.9 BYK-340 0.1 0.1 0.1 0.1 0.1 SolbinCL 1 1 1 1 1 Discharge stability 3 4 3 4 4 Intensity 5 5 5 4 4 Weatherresistance 4 4 3 4 4 Abrasion resistance 2 3 3 4 4

TABLE 4 Example Example Example Example Comparative Comparative 12 13 1415 Example 1 Example 2 PR-254 particle diameter: 50 nm — — — — 3.0 —PR-254 particle diameter: 85 nm — — — — — 3.0 PR-254 particle diameter:103 nm — — — — — — PR-254 particle diameter: 170 nm 3.0 3.0 3.0 3.0 — —PR-254 particle diameter: 238 nm — — — — — — PR-254 particle diameter:252 nm — — — — — — PR-254 particle diameter: 310 nm — — — — — — PR-177particle diameter: 175 nm — — — — — — PR-179 particle diameter: 183 nm —— — — — — PR-224 particle diameter: 168 nm — — — — — — Diethylene glycolmethyl ethyl ether (flash point: 64° C.) 50 50 34 84 50 50 Diethyleneglycol diethyl ether (flash point: 71° C.) — — — — — — Tetraethyleneglycol dimethyl ether (flash point: 141° C.) — — — — — — Triethyleneglycol monobutyl ether (flash point: 143° C.) — 34 50 — 34 34Tetraethylene glycol monobutyl ether — — — — — — Dipropylene glycolmonomethyl ether (flash point: 79° C.) — — — — — — Ethylene glycolmonobutyl ether (flash point: 62° C.) 34 — — — — — Gamma-butyrolactone10 — 10 10 10 10 Delta-valerolactone — 10 — — — — Solsperse 37500 1.91.9 1.9 1.9 1.9 1.9 BYK-340 0.1 0.1 0.1 0.1 0.1 0.1 Solbin CL 1 1 1 1 11 Discharge stability 4 4 3 4 4 4 Intensity 4 4 3 3 1 2 Weatherresistance 4 4 4 4 1 2 Abrasion resistance 4 4 3 4 4 4 ComparativeComparative Comparative Comparative Comparative Example 3 Example 4Example 5 Example 6 Example 7 PR-254 particle diameter: 50 nm — — — — —PR-254 particle diameter: 85 nm — — — — — PR-254 particle diameter: 103nm — — — — — PR-254 particle diameter: 170 nm — — — — — PR-254 particlediameter: 238 nm — — — — — PR-254 particle diameter: 252 nm 3.0 — — — —PR-254 particle diameter: 310 nm — 3.0 — — — PR-177 particle diameter:175 nm — — 3.0 — — PR-179 particle diameter: 183 nm — — — 3.0 — PR-224particle diameter: 168 nm — — — — 3.0 Diethylene glycol methyl ethylether (flash point: 64° C.) 50 50 50 50 50 Diethylene glycol diethylether (flash point: 71° C.) — — — — — Tetraethylene glycol dimethylether (flash point: 141° C.) — — — — — Triethylene glycol monobutylether (flash point: 143° C.) 34 34 34 34 34 Tetraethylene glycolmonobutyl ether — — — — — Dipropylene glycol monomethyl ether (flashpoint: 79° C.) — — — — — Ethylene glycol monobutyl ether (flash point:62° C.) — — — — — Gamma-butyrolactone 10 10 10 10 10 Delta-valerolactone— — — — — Solsperse 37500 1.9 1.9 1.9 1.9 1.9 BYK-340 0.1 0.1 0.1 0.10.1 Solbin CL 1 1 1 1 1 Discharge stability 2 1 4 4 4 Intensity 5 5 2 12 Weather resistance 4 4 4 4 4 Abrasion resistance 4 4 4 4 4Formation of Recorded Matter

A PVC medium (manufactured by 3M Company, Model No. IJ180-10) as arecording medium was placed in an ink jet printer (manufactured by SeikoEpson Corporation, trade name: SC-530650); any of the compositionsprepared in Examples, Comparative Examples, and Reference Examples wasloaded into the discharge head; the temperature of the platen wasmaintained at 45° C. during the formation of a recorded matter and for 1minute after the formation of the recorded matter; and a solid patternwas formed at an application amount of 10 mg/inch² and a targetresolution of 720×720 dpi to give each recorded matter. Even if aninsufficient discharge part was caused by a discharge defect, thedefective portion was not compensated.

Evaluation 1: Discharge Stability

Any of the compositions prepared in Examples, Comparative Examples, andReference Examples was loaded on an ink jet printer (manufactured bySeiko Epson Corporation, trade name: SC-530650) and was then dischargedfrom an ink jet head having 360 nozzles at a frequency of 7 kHz tocontinuously form solid patterns (L dot, 600×600 dpi) for 300 seconds ona PVC medium (manufactured by 3M Company, Model No. IJ180-10) as arecording medium, and the discharge was then stopped. This procedure wasdefined as one sequence. Subsequently, the procedure was repeated tensequences. The thus-prepared solid patterns as recorded matters wereinvestigated for dot omission, curved flight, and scattering of the ink.The nozzle having any of these phenomena was defined as a defectivenozzle, and the rate of defective nozzles to the total nozzles wascounted to evaluate discharge stability. The results are shown in Tables3 and 4.

Evaluation Criteria

-   -   4: the number of defective nozzles is zero,    -   3: the number of defective nozzles is one or two,    -   2: the number of defective nozzles is three or four, and    -   1: the number of defective nozzles is five or more.        Evaluation 2: Intensity

The intensity (C*) of each of the resulting recorded matters wasevaluated. Specifically, the value a* and the value b* of each recordedmatter were measured with a spectrophotometer (manufactured byGretagMacbeth, trade name: Spectrolino), and the value C* wascalculated. The intensity was evaluated based on the followingevaluation criteria. The calculated value C* was rounded off to thenearest whole number. The results are shown in Tables 3 and 4.

Evaluation Criteria

-   -   5: value C* of 110 or more,    -   4: value of 100 to 109,    -   3: value C* of 90 to 99,    -   2: value C* of 80 to 89, and    -   1: value C* of 79 or less.        Evaluation 3: Weather Resistance

Recorded matters were formed using the compositions prepared inExamples, Comparative Examples, and Reference Examples as in the aboveexcept that the Duty was adjusted such that the initial OD valuemeasured with a Gretag densitometer (manufactured by GretagMacbeth) was0.5, 1.0, or the maximum. The resulting recorded matters were placed inthe chamber of a xenon weather meter (manufactured by Suga TestInstruments Co., Ltd.) and were subjected to a cycle test repeating acycle consisting of light irradiation for 40 minutes, light irradiationand waterfall (rainfall) for 20 minutes, light irradiation for 60minutes, and waterfall (rainfall) for 60 minutes in this order under thetest conditions shown in Table 5. This cycle test was continued for 4weeks, and the recorded matters were taken out after 4 weeks. The ODvalues of the recorded matters were measured with a Gretag densitometer(manufactured by GretagMacbeth) to determine the survival rate (%) ofthe OD value. Among the recorded matters of which the initial OD valuesadjusted to 0.5, 1.0, and the maximum, the recorded matter having thelowest survival rate was used as the subject for evaluation of weatherresistance based on the following evaluation criteria. The results areshown in Tables 3 and 4.

Evaluation Criteria

-   -   4: OD value survival rate of 90% or more    -   3: OD value survival rate of 80% or more and less than 90%    -   2: OD value survival rate of 70% or more and less than 80%, and    -   1: OD value survival rate of less than 70%

TABLE 5 Irradiation Irradiation intensity intensity In-tank RelativeCycle Time 340 nm 300-400 nm BPT temperature humidity Pure water segment(min) (W/m²) (W/m²) (° C.) (° C.) (%) spray 1 40 0.55 ± 0.02 60 ± 2 63 ±2 40 ± 2 50 ± 6 None 2 20 0.55 ± 0.02 60 ± 2 63 ± 2 40 ± 2 — Front 3 600.55 ± 0.02 60 ± 2 63 ± 2 40 ± 2 50 ± 6 None 4 60 0 0 38 ± 2 38 ± 2 —FrontEvaluation 4: Abrasion Resistance

Each of the resulting recorded matters was rubbed with an abrader havinga cotton cloth (unbleached muslin: No. 20) under a load of 500 g with aGakushin-type rubbing fastness tester (manufactured by Tester SangyoCo., Ltd., trade name: AB-301) for 20 times in a reciprocating motion inaccordance with JIS K5701 (ISO 11628). Abrasion resistance was evaluatedby visually observing the recorded matter on the recording medium forscratch and detachment based on the following evaluation criteria. Theresults are shown in Tables 3 and 4.

Evaluation Criteria

-   -   4: No scratch and no detachment were observed in the recorded        matter after the rubbing for 20 times in a reciprocating motion;    -   3: No detachment was observed in the recorded matter after        rubbing for 20 times in a reciprocating motion, but scratch was        observed;    -   2: Detachment and scratch were partially observed in the        recorded matter after rubbing for 20 times in a reciprocating        motion; and    -   1: Detachment was observed in the recorded matter over a part        after rubbing for 20 times in a reciprocating motion.

The comparison among the results of Examples, Comparative Examples, andReference Examples shown in Tables 3 and 4 demonstrated that thenon-aqueous ink jet compositions according to the present invention canform recorded matters having excellent intensity, weather resistance,and abrasion resistance and that the non-aqueous ink jet compositionsalso have excellent discharge stability.

The entire disclosures of Japanese Patent Application No. 2016-013478,filed Jan. 27, 2016 and 2016-013527, filed Jan. 27, 2016 are expresslyincorporated by reference herein.

What is claimed is:
 1. A non-aqueous ink jet composition comprising: apigment component containing a diketopyrrolopyrrole pigment; and anorganic solvent, wherein the organic solvent contains glycol ethers; andthe non-aqueous ink jet composition contains gaseous nitrogen dissolvedtherein in an amount of 90 mass ppm or less based on the total amount ofthe non-aqueous ink jet composition.
 2. The non-aqueous ink jetcomposition according to claim 1, wherein the amount of gaseous nitrogendissolved therein is 10 mass ppm or more based on the total amount ofthe non-aqueous ink jet composition.
 3. The non-aqueous ink jetcomposition according to claim 1, wherein the glycol ethers include aglycol diether represented by Formula (1):R¹O—(R³O)_(m)—R²  (1) where, R¹ and R² each independently represent analkyl group having 1 to 7 carbon atoms, R³ represents an alkylene grouphaving 1 to 3 carbon atoms, and m represents an integer of 1 to
 7. 4.The non-aqueous ink jet composition according to claim 1, wherein theglycol ethers include a glycol monoether represented by Formula (2):OH—(R⁵O)_(n)—R⁴  (2) where, R⁴ represents an alkyl group having 1 to 7carbon atoms, R⁵ represents an alkylene group having 1 to 3 carbonatoms, and n represents an integer of 1 to
 7. 5. The non-aqueous ink jetcomposition according to claim 1, wherein the amount of the pigmentcomponent is 1.0 mass % or more and 5.0 mass % or less based on thetotal amount of the non-aqueous ink jet composition.
 6. The non-aqueousink jet composition according to claim 1, wherein the amount of theglycol ethers is 10 mass % or more and 90 mass % or less based on thetotal amount of the non-aqueous ink jet composition.
 7. The non-aqueousink jet composition according to claim 1, wherein the organic solventfurther contains a cyclic lactone.
 8. The non-aqueous ink jetcomposition according to claim 1, further comprising a vinyl chlorideresin.
 9. An ink jet recording method comprising: performing recordingon a recording medium by an ink jet method using the non-aqueous ink jetcomposition according to claim 1.